diff.c

   1 /*
   2  * Copyright (C) 2005 Junio C Hamano
   3  */
   4 #include "cache.h"
   5 #include "quote.h"
   6 #include "diff.h"
   7 #include "diffcore.h"
   8 #include "delta.h"
   9 #include "xdiff-interface.h"
  10 #include "color.h"
  11 #include "attr.h"
  12 #include "run-command.h"
  13 #include "utf8.h"
  14
  15 #ifdef NO_FAST_WORKING_DIRECTORY
  16 #define FAST_WORKING_DIRECTORY 0
  17 #else
  18 #define FAST_WORKING_DIRECTORY 1
  19 #endif
  20
  21 static int diff_detect_rename_default;
  22 static int diff_rename_limit_default = 100;
  23 int diff_use_color_default = -1;
  24 static const char *external_diff_cmd_cfg;
  25 int diff_auto_refresh_index = 1;
  26
  27 static char diff_colors[][COLOR_MAXLEN] = {
  28         "\033[m",       /* reset */
  29         "",             /* PLAIN (normal) */
  30         "\033[1m",      /* METAINFO (bold) */
  31         "\033[36m",     /* FRAGINFO (cyan) */
  32         "\033[31m",     /* OLD (red) */
  33         "\033[32m",     /* NEW (green) */
  34         "\033[33m",     /* COMMIT (yellow) */
  35         "\033[41m",     /* WHITESPACE (red background) */
  36 };
  37
  38 static int parse_diff_color_slot(const char *var, int ofs)
  39 {
  40         if (!strcasecmp(var+ofs, "plain"))
  41                 return DIFF_PLAIN;
  42         if (!strcasecmp(var+ofs, "meta"))
  43                 return DIFF_METAINFO;
  44         if (!strcasecmp(var+ofs, "frag"))
  45                 return DIFF_FRAGINFO;
  46         if (!strcasecmp(var+ofs, "old"))
  47                 return DIFF_FILE_OLD;
  48         if (!strcasecmp(var+ofs, "new"))
  49                 return DIFF_FILE_NEW;
  50         if (!strcasecmp(var+ofs, "commit"))
  51                 return DIFF_COMMIT;
  52         if (!strcasecmp(var+ofs, "whitespace"))
  53                 return DIFF_WHITESPACE;
  54         die("bad config variable '%s'", var);
  55 }
  56
  57 static struct ll_diff_driver {
  58         const char *name;
  59         struct ll_diff_driver *next;
  60         const char *cmd;
  61 } *user_diff, **user_diff_tail;
  62
  63 /*
  64  * Currently there is only "diff.<drivername>.command" variable;
  65  * because there are "diff.color.<slot>" variables, we are parsing
  66  * this in a bit convoluted way to allow low level diff driver
  67  * called "color".
  68  */
  69 static int parse_lldiff_command(const char *var, const char *ep, const char *value)
  70 {
  71         const char *name;
  72         int namelen;
  73         struct ll_diff_driver *drv;
  74
  75         name = var + 5;
  76         namelen = ep - name;
  77         for (drv = user_diff; drv; drv = drv->next)
  78                 if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
  79                         break;
  80         if (!drv) {
  81                 drv = xcalloc(1, sizeof(struct ll_diff_driver));
  82                 drv->name = xmemdupz(name, namelen);
  83                 if (!user_diff_tail)
  84                         user_diff_tail = &user_diff;
  85                 *user_diff_tail = drv;
  86                 user_diff_tail = &(drv->next);
  87         }
  88
  89         return git_config_string(&(drv->cmd), var, value);
  90 }
  91
  92 /*
  93  * 'diff.<what>.funcname' attribute can be specified in the configuration
  94  * to define a customized regexp to find the beginning of a function to
  95  * be used for hunk header lines of "diff -p" style output.
  96  */
  97 static struct funcname_pattern {
  98         char *name;
  99         char *pattern;
 100         struct funcname_pattern *next;
 101 } *funcname_pattern_list;
 102
 103 static int parse_funcname_pattern(const char *var, const char *ep, const char *value)
 104 {
 105         const char *name;
 106         int namelen;
 107         struct funcname_pattern *pp;
 108
 109         name = var + 5; /* "diff." */
 110         namelen = ep - name;
 111
 112         for (pp = funcname_pattern_list; pp; pp = pp->next)
 113                 if (!strncmp(pp->name, name, namelen) && !pp->name[namelen])
 114                         break;
 115         if (!pp) {
 116                 pp = xcalloc(1, sizeof(*pp));
 117                 pp->name = xmemdupz(name, namelen);
 118                 pp->next = funcname_pattern_list;
 119                 funcname_pattern_list = pp;
 120         }
 121         free(pp->pattern);
 122         pp->pattern = xstrdup(value);
 123         return 0;
 124 }
 125
 126 /*
 127  * These are to give UI layer defaults.
 128  * The core-level commands such as git-diff-files should
 129  * never be affected by the setting of diff.renames
 130  * the user happens to have in the configuration file.
 131  */
 132 int git_diff_ui_config(const char *var, const char *value)
 133 {
 134         if (!strcmp(var, "diff.renamelimit")) {
 135                 diff_rename_limit_default = git_config_int(var, value);
 136                 return 0;
 137         }
 138         if (!strcmp(var, "diff.color") || !strcmp(var, "color.diff")) {
 139                 diff_use_color_default = git_config_colorbool(var, value, -1);
 140                 return 0;
 141         }
 142         if (!strcmp(var, "diff.renames")) {
 143                 if (!value)
 144                         diff_detect_rename_default = DIFF_DETECT_RENAME;
 145                 else if (!strcasecmp(value, "copies") ||
 146                          !strcasecmp(value, "copy"))
 147                         diff_detect_rename_default = DIFF_DETECT_COPY;
 148                 else if (git_config_bool(var,value))
 149                         diff_detect_rename_default = DIFF_DETECT_RENAME;
 150                 return 0;
 151         }
 152         if (!strcmp(var, "diff.autorefreshindex")) {
 153                 diff_auto_refresh_index = git_config_bool(var, value);
 154                 return 0;
 155         }
 156         if (!strcmp(var, "diff.external")) {
 157                 if (!value)
 158                         return config_error_nonbool(var);
 159                 external_diff_cmd_cfg = xstrdup(value);
 160                 return 0;
 161         }
 162         if (!prefixcmp(var, "diff.")) {
 163                 const char *ep = strrchr(var, '.');
 164
 165                 if (ep != var + 4 && !strcmp(ep, ".command"))
 166                         return parse_lldiff_command(var, ep, value);
 167         }
 168
 169         return git_diff_basic_config(var, value);
 170 }
 171
 172 int git_diff_basic_config(const char *var, const char *value)
 173 {
 174         if (!prefixcmp(var, "diff.color.") || !prefixcmp(var, "color.diff.")) {
 175                 int slot = parse_diff_color_slot(var, 11);
 176                 if (!value)
 177                         return config_error_nonbool(var);
 178                 color_parse(value, var, diff_colors[slot]);
 179                 return 0;
 180         }
 181
 182         if (!prefixcmp(var, "diff.")) {
 183                 const char *ep = strrchr(var, '.');
 184                 if (ep != var + 4) {
 185                         if (!strcmp(ep, ".funcname")) {
 186                                 if (!value)
 187                                         return config_error_nonbool(var);
 188                                 return parse_funcname_pattern(var, ep, value);
 189                         }
 190                 }
 191         }
 192
 193         return git_color_default_config(var, value);
 194 }
 195
 196 static char *quote_two(const char *one, const char *two)
 197 {
 198         int need_one = quote_c_style(one, NULL, NULL, 1);
 199         int need_two = quote_c_style(two, NULL, NULL, 1);
 200         struct strbuf res;
 201
 202         strbuf_init(&res, 0);
 203         if (need_one + need_two) {
 204                 strbuf_addch(&res, '"');
 205                 quote_c_style(one, &res, NULL, 1);
 206                 quote_c_style(two, &res, NULL, 1);
 207                 strbuf_addch(&res, '"');
 208         } else {
 209                 strbuf_addstr(&res, one);
 210                 strbuf_addstr(&res, two);
 211         }
 212         return strbuf_detach(&res, NULL);
 213 }
 214
 215 static const char *external_diff(void)
 216 {
 217         static const char *external_diff_cmd = NULL;
 218         static int done_preparing = 0;
 219
 220         if (done_preparing)
 221                 return external_diff_cmd;
 222         external_diff_cmd = getenv("GIT_EXTERNAL_DIFF");
 223         if (!external_diff_cmd)
 224                 external_diff_cmd = external_diff_cmd_cfg;
 225         done_preparing = 1;
 226         return external_diff_cmd;
 227 }
 228
 229 static struct diff_tempfile {
 230         const char *name; /* filename external diff should read from */
 231         char hex[41];
 232         char mode[10];
 233         char tmp_path[PATH_MAX];
 234 } diff_temp[2];
 235
 236 static int count_lines(const char *data, int size)
 237 {
 238         int count, ch, completely_empty = 1, nl_just_seen = 0;
 239         count = 0;
 240         while (0 < size--) {
 241                 ch = *data++;
 242                 if (ch == '\n') {
 243                         count++;
 244                         nl_just_seen = 1;
 245                         completely_empty = 0;
 246                 }
 247                 else {
 248                         nl_just_seen = 0;
 249                         completely_empty = 0;
 250                 }
 251         }
 252         if (completely_empty)
 253                 return 0;
 254         if (!nl_just_seen)
 255                 count++; /* no trailing newline */
 256         return count;
 257 }
 258
 259 static void print_line_count(FILE *file, int count)
 260 {
 261         switch (count) {
 262         case 0:
 263                 fprintf(file, "0,0");
 264                 break;
 265         case 1:
 266                 fprintf(file, "1");
 267                 break;
 268         default:
 269                 fprintf(file, "1,%d", count);
 270                 break;
 271         }
 272 }
 273
 274 static void copy_file_with_prefix(FILE *file,
 275                                   int prefix, const char *data, int size,
 276                                   const char *set, const char *reset)
 277 {
 278         int ch, nl_just_seen = 1;
 279         while (0 < size--) {
 280                 ch = *data++;
 281                 if (nl_just_seen) {
 282                         fputs(set, file);
 283                         putc(prefix, file);
 284                 }
 285                 if (ch == '\n') {
 286                         nl_just_seen = 1;
 287                         fputs(reset, file);
 288                 } else
 289                         nl_just_seen = 0;
 290                 putc(ch, file);
 291         }
 292         if (!nl_just_seen)
 293                 fprintf(file, "%s\n\\ No newline at end of file\n", reset);
 294 }
 295
 296 static void emit_rewrite_diff(const char *name_a,
 297                               const char *name_b,
 298                               struct diff_filespec *one,
 299                               struct diff_filespec *two,
 300                               struct diff_options *o)
 301 {
 302         int lc_a, lc_b;
 303         int color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
 304         const char *name_a_tab, *name_b_tab;
 305         const char *metainfo = diff_get_color(color_diff, DIFF_METAINFO);
 306         const char *fraginfo = diff_get_color(color_diff, DIFF_FRAGINFO);
 307         const char *old = diff_get_color(color_diff, DIFF_FILE_OLD);
 308         const char *new = diff_get_color(color_diff, DIFF_FILE_NEW);
 309         const char *reset = diff_get_color(color_diff, DIFF_RESET);
 310         static struct strbuf a_name = STRBUF_INIT, b_name = STRBUF_INIT;
 311
 312         name_a += (*name_a == '/');
 313         name_b += (*name_b == '/');
 314         name_a_tab = strchr(name_a, ' ') ? "\t" : "";
 315         name_b_tab = strchr(name_b, ' ') ? "\t" : "";
 316
 317         strbuf_reset(&a_name);
 318         strbuf_reset(&b_name);
 319         quote_two_c_style(&a_name, o->a_prefix, name_a, 0);
 320         quote_two_c_style(&b_name, o->b_prefix, name_b, 0);
 321
 322         diff_populate_filespec(one, 0);
 323         diff_populate_filespec(two, 0);
 324         lc_a = count_lines(one->data, one->size);
 325         lc_b = count_lines(two->data, two->size);
 326         fprintf(o->file,
 327                 "%s--- %s%s%s\n%s+++ %s%s%s\n%s@@ -",
 328                 metainfo, a_name.buf, name_a_tab, reset,
 329                 metainfo, b_name.buf, name_b_tab, reset, fraginfo);
 330         print_line_count(o->file, lc_a);
 331         fprintf(o->file, " +");
 332         print_line_count(o->file, lc_b);
 333         fprintf(o->file, " @@%s\n", reset);
 334         if (lc_a)
 335                 copy_file_with_prefix(o->file, '-', one->data, one->size, old, reset);
 336         if (lc_b)
 337                 copy_file_with_prefix(o->file, '+', two->data, two->size, new, reset);
 338 }
 339
 340 static int fill_mmfile(mmfile_t *mf, struct diff_filespec *one)
 341 {
 342         if (!DIFF_FILE_VALID(one)) {
 343                 mf->ptr = (char *)""; /* does not matter */
 344                 mf->size = 0;
 345                 return 0;
 346         }
 347         else if (diff_populate_filespec(one, 0))
 348                 return -1;
 349         mf->ptr = one->data;
 350         mf->size = one->size;
 351         return 0;
 352 }
 353
 354 struct diff_words_buffer {
 355         mmfile_t text;
 356         long alloc;
 357         long current; /* output pointer */
 358         int suppressed_newline;
 359 };
 360
 361 static void diff_words_append(char *line, unsigned long len,
 362                 struct diff_words_buffer *buffer)
 363 {
 364         if (buffer->text.size + len > buffer->alloc) {
 365                 buffer->alloc = (buffer->text.size + len) * 3 / 2;
 366                 buffer->text.ptr = xrealloc(buffer->text.ptr, buffer->alloc);
 367         }
 368         line++;
 369         len--;
 370         memcpy(buffer->text.ptr + buffer->text.size, line, len);
 371         buffer->text.size += len;
 372 }
 373
 374 struct diff_words_data {
 375         struct xdiff_emit_state xm;
 376         struct diff_words_buffer minus, plus;
 377         FILE *file;
 378 };
 379
 380 static void print_word(FILE *file, struct diff_words_buffer *buffer, int len, int color,
 381                 int suppress_newline)
 382 {
 383         const char *ptr;
 384         int eol = 0;
 385
 386         if (len == 0)
 387                 return;
 388
 389         ptr  = buffer->text.ptr + buffer->current;
 390         buffer->current += len;
 391
 392         if (ptr[len - 1] == '\n') {
 393                 eol = 1;
 394                 len--;
 395         }
 396
 397         fputs(diff_get_color(1, color), file);
 398         fwrite(ptr, len, 1, file);
 399         fputs(diff_get_color(1, DIFF_RESET), file);
 400
 401         if (eol) {
 402                 if (suppress_newline)
 403                         buffer->suppressed_newline = 1;
 404                 else
 405                         putc('\n', file);
 406         }
 407 }
 408
 409 static void fn_out_diff_words_aux(void *priv, char *line, unsigned long len)
 410 {
 411         struct diff_words_data *diff_words = priv;
 412
 413         if (diff_words->minus.suppressed_newline) {
 414                 if (line[0] != '+')
 415                         putc('\n', diff_words->file);
 416                 diff_words->minus.suppressed_newline = 0;
 417         }
 418
 419         len--;
 420         switch (line[0]) {
 421                 case '-':
 422                         print_word(diff_words->file,
 423                                    &diff_words->minus, len, DIFF_FILE_OLD, 1);
 424                         break;
 425                 case '+':
 426                         print_word(diff_words->file,
 427                                    &diff_words->plus, len, DIFF_FILE_NEW, 0);
 428                         break;
 429                 case ' ':
 430                         print_word(diff_words->file,
 431                                    &diff_words->plus, len, DIFF_PLAIN, 0);
 432                         diff_words->minus.current += len;
 433                         break;
 434         }
 435 }
 436
 437 /* this executes the word diff on the accumulated buffers */
 438 static void diff_words_show(struct diff_words_data *diff_words)
 439 {
 440         xpparam_t xpp;
 441         xdemitconf_t xecfg;
 442         xdemitcb_t ecb;
 443         mmfile_t minus, plus;
 444         int i;
 445
 446         memset(&xecfg, 0, sizeof(xecfg));
 447         minus.size = diff_words->minus.text.size;
 448         minus.ptr = xmalloc(minus.size);
 449         memcpy(minus.ptr, diff_words->minus.text.ptr, minus.size);
 450         for (i = 0; i < minus.size; i++)
 451                 if (isspace(minus.ptr[i]))
 452                         minus.ptr[i] = '\n';
 453         diff_words->minus.current = 0;
 454
 455         plus.size = diff_words->plus.text.size;
 456         plus.ptr = xmalloc(plus.size);
 457         memcpy(plus.ptr, diff_words->plus.text.ptr, plus.size);
 458         for (i = 0; i < plus.size; i++)
 459                 if (isspace(plus.ptr[i]))
 460                         plus.ptr[i] = '\n';
 461         diff_words->plus.current = 0;
 462
 463         xpp.flags = XDF_NEED_MINIMAL;
 464         xecfg.ctxlen = diff_words->minus.alloc + diff_words->plus.alloc;
 465         ecb.outf = xdiff_outf;
 466         ecb.priv = diff_words;
 467         diff_words->xm.consume = fn_out_diff_words_aux;
 468         xdi_diff(&minus, &plus, &xpp, &xecfg, &ecb);
 469
 470         free(minus.ptr);
 471         free(plus.ptr);
 472         diff_words->minus.text.size = diff_words->plus.text.size = 0;
 473
 474         if (diff_words->minus.suppressed_newline) {
 475                 putc('\n', diff_words->file);
 476                 diff_words->minus.suppressed_newline = 0;
 477         }
 478 }
 479
 480 typedef unsigned long (*sane_truncate_fn)(char *line, unsigned long len);
 481
 482 struct emit_callback {
 483         struct xdiff_emit_state xm;
 484         int nparents, color_diff;
 485         unsigned ws_rule;
 486         sane_truncate_fn truncate;
 487         const char **label_path;
 488         struct diff_words_data *diff_words;
 489         int *found_changesp;
 490         FILE *file;
 491 };
 492
 493 static void free_diff_words_data(struct emit_callback *ecbdata)
 494 {
 495         if (ecbdata->diff_words) {
 496                 /* flush buffers */
 497                 if (ecbdata->diff_words->minus.text.size ||
 498                                 ecbdata->diff_words->plus.text.size)
 499                         diff_words_show(ecbdata->diff_words);
 500
 501                 free (ecbdata->diff_words->minus.text.ptr);
 502                 free (ecbdata->diff_words->plus.text.ptr);
 503                 free(ecbdata->diff_words);
 504                 ecbdata->diff_words = NULL;
 505         }
 506 }
 507
 508 const char *diff_get_color(int diff_use_color, enum color_diff ix)
 509 {
 510         if (diff_use_color)
 511                 return diff_colors[ix];
 512         return "";
 513 }
 514
 515 static void emit_line(FILE *file, const char *set, const char *reset, const char *line, int len)
 516 {
 517         if (len > 0 && line[len-1] == '\n')
 518                 len--;
 519
 520         fputs(set, file);
 521         fwrite(line, len, 1, file);
 522         fputs(reset, file);
 523         fputc('\n', file);
 524 }
 525
 526 static void emit_add_line(const char *reset, struct emit_callback *ecbdata, const char *line, int len)
 527 {
 528         const char *ws = diff_get_color(ecbdata->color_diff, DIFF_WHITESPACE);
 529         const char *set = diff_get_color(ecbdata->color_diff, DIFF_FILE_NEW);
 530
 531         if (!*ws)
 532                 emit_line(ecbdata->file, set, reset, line, len);
 533         else {
 534                 /* Emit just the prefix, then the rest. */
 535                 emit_line(ecbdata->file, set, reset, line, ecbdata->nparents);
 536                 (void)check_and_emit_line(line + ecbdata->nparents,
 537                     len - ecbdata->nparents, ecbdata->ws_rule,
 538                     ecbdata->file, set, reset, ws);
 539         }
 540 }
 541
 542 static unsigned long sane_truncate_line(struct emit_callback *ecb, char *line, unsigned long len)
 543 {
 544         const char *cp;
 545         unsigned long allot;
 546         size_t l = len;
 547
 548         if (ecb->truncate)
 549                 return ecb->truncate(line, len);
 550         cp = line;
 551         allot = l;
 552         while (0 < l) {
 553                 (void) utf8_width(&cp, &l);
 554                 if (!cp)
 555                         break; /* truncated in the middle? */
 556         }
 557         return allot - l;
 558 }
 559
 560 static void fn_out_consume(void *priv, char *line, unsigned long len)
 561 {
 562         int i;
 563         int color;
 564         struct emit_callback *ecbdata = priv;
 565         const char *meta = diff_get_color(ecbdata->color_diff, DIFF_METAINFO);
 566         const char *plain = diff_get_color(ecbdata->color_diff, DIFF_PLAIN);
 567         const char *reset = diff_get_color(ecbdata->color_diff, DIFF_RESET);
 568
 569         *(ecbdata->found_changesp) = 1;
 570
 571         if (ecbdata->label_path[0]) {
 572                 const char *name_a_tab, *name_b_tab;
 573
 574                 name_a_tab = strchr(ecbdata->label_path[0], ' ') ? "\t" : "";
 575                 name_b_tab = strchr(ecbdata->label_path[1], ' ') ? "\t" : "";
 576
 577                 fprintf(ecbdata->file, "%s--- %s%s%s\n",
 578                         meta, ecbdata->label_path[0], reset, name_a_tab);
 579                 fprintf(ecbdata->file, "%s+++ %s%s%s\n",
 580                         meta, ecbdata->label_path[1], reset, name_b_tab);
 581                 ecbdata->label_path[0] = ecbdata->label_path[1] = NULL;
 582         }
 583
 584         /* This is not really necessary for now because
 585          * this codepath only deals with two-way diffs.
 586          */
 587         for (i = 0; i < len && line[i] == '@'; i++)
 588                 ;
 589         if (2 <= i && i < len && line[i] == ' ') {
 590                 ecbdata->nparents = i - 1;
 591                 len = sane_truncate_line(ecbdata, line, len);
 592                 emit_line(ecbdata->file,
 593                           diff_get_color(ecbdata->color_diff, DIFF_FRAGINFO),
 594                           reset, line, len);
 595                 if (line[len-1] != '\n')
 596                         putc('\n', ecbdata->file);
 597                 return;
 598         }
 599
 600         if (len < ecbdata->nparents) {
 601                 emit_line(ecbdata->file, reset, reset, line, len);
 602                 return;
 603         }
 604
 605         color = DIFF_PLAIN;
 606         if (ecbdata->diff_words && ecbdata->nparents != 1)
 607                 /* fall back to normal diff */
 608                 free_diff_words_data(ecbdata);
 609         if (ecbdata->diff_words) {
 610                 if (line[0] == '-') {
 611                         diff_words_append(line, len,
 612                                           &ecbdata->diff_words->minus);
 613                         return;
 614                 } else if (line[0] == '+') {
 615                         diff_words_append(line, len,
 616                                           &ecbdata->diff_words->plus);
 617                         return;
 618                 }
 619                 if (ecbdata->diff_words->minus.text.size ||
 620                     ecbdata->diff_words->plus.text.size)
 621                         diff_words_show(ecbdata->diff_words);
 622                 line++;
 623                 len--;
 624                 emit_line(ecbdata->file, plain, reset, line, len);
 625                 return;
 626         }
 627         for (i = 0; i < ecbdata->nparents && len; i++) {
 628                 if (line[i] == '-')
 629                         color = DIFF_FILE_OLD;
 630                 else if (line[i] == '+')
 631                         color = DIFF_FILE_NEW;
 632         }
 633
 634         if (color != DIFF_FILE_NEW) {
 635                 emit_line(ecbdata->file,
 636                           diff_get_color(ecbdata->color_diff, color),
 637                           reset, line, len);
 638                 return;
 639         }
 640         emit_add_line(reset, ecbdata, line, len);
 641 }
 642
 643 static char *pprint_rename(const char *a, const char *b)
 644 {
 645         const char *old = a;
 646         const char *new = b;
 647         struct strbuf name;
 648         int pfx_length, sfx_length;
 649         int len_a = strlen(a);
 650         int len_b = strlen(b);
 651         int a_midlen, b_midlen;
 652         int qlen_a = quote_c_style(a, NULL, NULL, 0);
 653         int qlen_b = quote_c_style(b, NULL, NULL, 0);
 654
 655         strbuf_init(&name, 0);
 656         if (qlen_a || qlen_b) {
 657                 quote_c_style(a, &name, NULL, 0);
 658                 strbuf_addstr(&name, " => ");
 659                 quote_c_style(b, &name, NULL, 0);
 660                 return strbuf_detach(&name, NULL);
 661         }
 662
 663         /* Find common prefix */
 664         pfx_length = 0;
 665         while (*old && *new && *old == *new) {
 666                 if (*old == '/')
 667                         pfx_length = old - a + 1;
 668                 old++;
 669                 new++;
 670         }
 671
 672         /* Find common suffix */
 673         old = a + len_a;
 674         new = b + len_b;
 675         sfx_length = 0;
 676         while (a <= old && b <= new && *old == *new) {
 677                 if (*old == '/')
 678                         sfx_length = len_a - (old - a);
 679                 old--;
 680                 new--;
 681         }
 682
 683         /*
 684          * pfx{mid-a => mid-b}sfx
 685          * {pfx-a => pfx-b}sfx
 686          * pfx{sfx-a => sfx-b}
 687          * name-a => name-b
 688          */
 689         a_midlen = len_a - pfx_length - sfx_length;
 690         b_midlen = len_b - pfx_length - sfx_length;
 691         if (a_midlen < 0)
 692                 a_midlen = 0;
 693         if (b_midlen < 0)
 694                 b_midlen = 0;
 695
 696         strbuf_grow(&name, pfx_length + a_midlen + b_midlen + sfx_length + 7);
 697         if (pfx_length + sfx_length) {
 698                 strbuf_add(&name, a, pfx_length);
 699                 strbuf_addch(&name, '{');
 700         }
 701         strbuf_add(&name, a + pfx_length, a_midlen);
 702         strbuf_addstr(&name, " => ");
 703         strbuf_add(&name, b + pfx_length, b_midlen);
 704         if (pfx_length + sfx_length) {
 705                 strbuf_addch(&name, '}');
 706                 strbuf_add(&name, a + len_a - sfx_length, sfx_length);
 707         }
 708         return strbuf_detach(&name, NULL);
 709 }
 710
 711 struct diffstat_t {
 712         struct xdiff_emit_state xm;
 713
 714         int nr;
 715         int alloc;
 716         struct diffstat_file {
 717                 char *from_name;
 718                 char *name;
 719                 char *print_name;
 720                 unsigned is_unmerged:1;
 721                 unsigned is_binary:1;
 722                 unsigned is_renamed:1;
 723                 unsigned int added, deleted;
 724         } **files;
 725 };
 726
 727 static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 728                                           const char *name_a,
 729                                           const char *name_b)
 730 {
 731         struct diffstat_file *x;
 732         x = xcalloc(sizeof (*x), 1);
 733         if (diffstat->nr == diffstat->alloc) {
 734                 diffstat->alloc = alloc_nr(diffstat->alloc);
 735                 diffstat->files = xrealloc(diffstat->files,
 736                                 diffstat->alloc * sizeof(x));
 737         }
 738         diffstat->files[diffstat->nr++] = x;
 739         if (name_b) {
 740                 x->from_name = xstrdup(name_a);
 741                 x->name = xstrdup(name_b);
 742                 x->is_renamed = 1;
 743         }
 744         else {
 745                 x->from_name = NULL;
 746                 x->name = xstrdup(name_a);
 747         }
 748         return x;
 749 }
 750
 751 static void diffstat_consume(void *priv, char *line, unsigned long len)
 752 {
 753         struct diffstat_t *diffstat = priv;
 754         struct diffstat_file *x = diffstat->files[diffstat->nr - 1];
 755
 756         if (line[0] == '+')
 757                 x->added++;
 758         else if (line[0] == '-')
 759                 x->deleted++;
 760 }
 761
 762 const char mime_boundary_leader[] = "------------";
 763
 764 static int scale_linear(int it, int width, int max_change)
 765 {
 766         /*
 767          * make sure that at least one '-' is printed if there were deletions,
 768          * and likewise for '+'.
 769          */
 770         if (max_change < 2)
 771                 return it;
 772         return ((it - 1) * (width - 1) + max_change - 1) / (max_change - 1);
 773 }
 774
 775 static void show_name(FILE *file,
 776                       const char *prefix, const char *name, int len,
 777                       const char *reset, const char *set)
 778 {
 779         fprintf(file, " %s%s%-*s%s |", set, prefix, len, name, reset);
 780 }
 781
 782 static void show_graph(FILE *file, char ch, int cnt, const char *set, const char *reset)
 783 {
 784         if (cnt <= 0)
 785                 return;
 786         fprintf(file, "%s", set);
 787         while (cnt--)
 788                 putc(ch, file);
 789         fprintf(file, "%s", reset);
 790 }
 791
 792 static void fill_print_name(struct diffstat_file *file)
 793 {
 794         char *pname;
 795
 796         if (file->print_name)
 797                 return;
 798
 799         if (!file->is_renamed) {
 800                 struct strbuf buf;
 801                 strbuf_init(&buf, 0);
 802                 if (quote_c_style(file->name, &buf, NULL, 0)) {
 803                         pname = strbuf_detach(&buf, NULL);
 804                 } else {
 805                         pname = file->name;
 806                         strbuf_release(&buf);
 807                 }
 808         } else {
 809                 pname = pprint_rename(file->from_name, file->name);
 810         }
 811         file->print_name = pname;
 812 }
 813
 814 static void show_stats(struct diffstat_t* data, struct diff_options *options)
 815 {
 816         int i, len, add, del, total, adds = 0, dels = 0;
 817         int max_change = 0, max_len = 0;
 818         int total_files = data->nr;
 819         int width, name_width;
 820         const char *reset, *set, *add_c, *del_c;
 821
 822         if (data->nr == 0)
 823                 return;
 824
 825         width = options->stat_width ? options->stat_width : 80;
 826         name_width = options->stat_name_width ? options->stat_name_width : 50;
 827
 828         /* Sanity: give at least 5 columns to the graph,
 829          * but leave at least 10 columns for the name.
 830          */
 831         if (width < name_width + 15) {
 832                 if (name_width <= 25)
 833                         width = name_width + 15;
 834                 else
 835                         name_width = width - 15;
 836         }
 837
 838         /* Find the longest filename and max number of changes */
 839         reset = diff_get_color_opt(options, DIFF_RESET);
 840         set   = diff_get_color_opt(options, DIFF_PLAIN);
 841         add_c = diff_get_color_opt(options, DIFF_FILE_NEW);
 842         del_c = diff_get_color_opt(options, DIFF_FILE_OLD);
 843
 844         for (i = 0; i < data->nr; i++) {
 845                 struct diffstat_file *file = data->files[i];
 846                 int change = file->added + file->deleted;
 847                 fill_print_name(file);
 848                 len = strlen(file->print_name);
 849                 if (max_len < len)
 850                         max_len = len;
 851
 852                 if (file->is_binary || file->is_unmerged)
 853                         continue;
 854                 if (max_change < change)
 855                         max_change = change;
 856         }
 857
 858         /* Compute the width of the graph part;
 859          * 10 is for one blank at the beginning of the line plus
 860          * " | count " between the name and the graph.
 861          *
 862          * From here on, name_width is the width of the name area,
 863          * and width is the width of the graph area.
 864          */
 865         name_width = (name_width < max_len) ? name_width : max_len;
 866         if (width < (name_width + 10) + max_change)
 867                 width = width - (name_width + 10);
 868         else
 869                 width = max_change;
 870
 871         for (i = 0; i < data->nr; i++) {
 872                 const char *prefix = "";
 873                 char *name = data->files[i]->print_name;
 874                 int added = data->files[i]->added;
 875                 int deleted = data->files[i]->deleted;
 876                 int name_len;
 877
 878                 /*
 879                  * "scale" the filename
 880                  */
 881                 len = name_width;
 882                 name_len = strlen(name);
 883                 if (name_width < name_len) {
 884                         char *slash;
 885                         prefix = "...";
 886                         len -= 3;
 887                         name += name_len - len;
 888                         slash = strchr(name, '/');
 889                         if (slash)
 890                                 name = slash;
 891                 }
 892
 893                 if (data->files[i]->is_binary) {
 894                         show_name(options->file, prefix, name, len, reset, set);
 895                         fprintf(options->file, "  Bin ");
 896                         fprintf(options->file, "%s%d%s", del_c, deleted, reset);
 897                         fprintf(options->file, " -> ");
 898                         fprintf(options->file, "%s%d%s", add_c, added, reset);
 899                         fprintf(options->file, " bytes");
 900                         fprintf(options->file, "\n");
 901                         continue;
 902                 }
 903                 else if (data->files[i]->is_unmerged) {
 904                         show_name(options->file, prefix, name, len, reset, set);
 905                         fprintf(options->file, "  Unmerged\n");
 906                         continue;
 907                 }
 908                 else if (!data->files[i]->is_renamed &&
 909                          (added + deleted == 0)) {
 910                         total_files--;
 911                         continue;
 912                 }
 913
 914                 /*
 915                  * scale the add/delete
 916                  */
 917                 add = added;
 918                 del = deleted;
 919                 total = add + del;
 920                 adds += add;
 921                 dels += del;
 922
 923                 if (width <= max_change) {
 924                         add = scale_linear(add, width, max_change);
 925                         del = scale_linear(del, width, max_change);
 926                         total = add + del;
 927                 }
 928                 show_name(options->file, prefix, name, len, reset, set);
 929                 fprintf(options->file, "%5d ", added + deleted);
 930                 show_graph(options->file, '+', add, add_c, reset);
 931                 show_graph(options->file, '-', del, del_c, reset);
 932                 fprintf(options->file, "\n");
 933         }
 934         fprintf(options->file,
 935                "%s %d files changed, %d insertions(+), %d deletions(-)%s\n",
 936                set, total_files, adds, dels, reset);
 937 }
 938
 939 static void show_shortstats(struct diffstat_t* data, struct diff_options *options)
 940 {
 941         int i, adds = 0, dels = 0, total_files = data->nr;
 942
 943         if (data->nr == 0)
 944                 return;
 945
 946         for (i = 0; i < data->nr; i++) {
 947                 if (!data->files[i]->is_binary &&
 948                     !data->files[i]->is_unmerged) {
 949                         int added = data->files[i]->added;
 950                         int deleted= data->files[i]->deleted;
 951                         if (!data->files[i]->is_renamed &&
 952                             (added + deleted == 0)) {
 953                                 total_files--;
 954                         } else {
 955                                 adds += added;
 956                                 dels += deleted;
 957                         }
 958                 }
 959         }
 960         fprintf(options->file, " %d files changed, %d insertions(+), %d deletions(-)\n",
 961                total_files, adds, dels);
 962 }
 963
 964 static void show_numstat(struct diffstat_t* data, struct diff_options *options)
 965 {
 966         int i;
 967
 968         if (data->nr == 0)
 969                 return;
 970
 971         for (i = 0; i < data->nr; i++) {
 972                 struct diffstat_file *file = data->files[i];
 973
 974                 if (file->is_binary)
 975                         fprintf(options->file, "-\t-\t");
 976                 else
 977                         fprintf(options->file,
 978                                 "%d\t%d\t", file->added, file->deleted);
 979                 if (options->line_termination) {
 980                         fill_print_name(file);
 981                         if (!file->is_renamed)
 982                                 write_name_quoted(file->name, options->file,
 983                                                   options->line_termination);
 984                         else {
 985                                 fputs(file->print_name, options->file);
 986                                 putc(options->line_termination, options->file);
 987                         }
 988                 } else {
 989                         if (file->is_renamed) {
 990                                 putc('\0', options->file);
 991                                 write_name_quoted(file->from_name, options->file, '\0');
 992                         }
 993                         write_name_quoted(file->name, options->file, '\0');
 994                 }
 995         }
 996 }
 997
 998 struct diffstat_dir {
 999         struct diffstat_file **files;
1000         int nr, percent, cumulative;
1001 };
1002
1003 static long gather_dirstat(FILE *file, struct diffstat_dir *dir, unsigned long changed, const char *base, int baselen)
1004 {
1005         unsigned long this_dir = 0;
1006         unsigned int sources = 0;
1007
1008         while (dir->nr) {
1009                 struct diffstat_file *f = *dir->files;
1010                 int namelen = strlen(f->name);
1011                 unsigned long this;
1012                 char *slash;
1013
1014                 if (namelen < baselen)
1015                         break;
1016                 if (memcmp(f->name, base, baselen))
1017                         break;
1018                 slash = strchr(f->name + baselen, '/');
1019                 if (slash) {
1020                         int newbaselen = slash + 1 - f->name;
1021                         this = gather_dirstat(file, dir, changed, f->name, newbaselen);
1022                         sources++;
1023                 } else {
1024                         if (f->is_unmerged || f->is_binary)
1025                                 this = 0;
1026                         else
1027                                 this = f->added + f->deleted;
1028                         dir->files++;
1029                         dir->nr--;
1030                         sources += 2;
1031                 }
1032                 this_dir += this;
1033         }
1034
1035         /*
1036          * We don't report dirstat's for
1037          *  - the top level
1038          *  - or cases where everything came from a single directory
1039          *    under this directory (sources == 1).
1040          */
1041         if (baselen && sources != 1) {
1042                 int permille = this_dir * 1000 / changed;
1043                 if (permille) {
1044                         int percent = permille / 10;
1045                         if (percent >= dir->percent) {
1046                                 fprintf(file, "%4d.%01d%% %.*s\n", percent, permille % 10, baselen, base);
1047                                 if (!dir->cumulative)
1048                                         return 0;
1049                         }
1050                 }
1051         }
1052         return this_dir;
1053 }
1054
1055 static void show_dirstat(struct diffstat_t *data, struct diff_options *options)
1056 {
1057         int i;
1058         unsigned long changed;
1059         struct diffstat_dir dir;
1060
1061         /* Calculate total changes */
1062         changed = 0;
1063         for (i = 0; i < data->nr; i++) {
1064                 if (data->files[i]->is_binary || data->files[i]->is_unmerged)
1065                         continue;
1066                 changed += data->files[i]->added;
1067                 changed += data->files[i]->deleted;
1068         }
1069
1070         /* This can happen even with many files, if everything was renames */
1071         if (!changed)
1072                 return;
1073
1074         /* Show all directories with more than x% of the changes */
1075         dir.files = data->files;
1076         dir.nr = data->nr;
1077         dir.percent = options->dirstat_percent;
1078         dir.cumulative = options->output_format & DIFF_FORMAT_CUMULATIVE;
1079         gather_dirstat(options->file, &dir, changed, "", 0);
1080 }
1081
1082 static void free_diffstat_info(struct diffstat_t *diffstat)
1083 {
1084         int i;
1085         for (i = 0; i < diffstat->nr; i++) {
1086                 struct diffstat_file *f = diffstat->files[i];
1087                 if (f->name != f->print_name)
1088                         free(f->print_name);
1089                 free(f->name);
1090                 free(f->from_name);
1091                 free(f);
1092         }
1093         free(diffstat->files);
1094 }
1095
1096 struct checkdiff_t {
1097         struct xdiff_emit_state xm;
1098         const char *filename;
1099         int lineno, color_diff;
1100         unsigned ws_rule;
1101         unsigned status;
1102         FILE *file;
1103 };
1104
1105 static void checkdiff_consume(void *priv, char *line, unsigned long len)
1106 {
1107         struct checkdiff_t *data = priv;
1108         const char *ws = diff_get_color(data->color_diff, DIFF_WHITESPACE);
1109         const char *reset = diff_get_color(data->color_diff, DIFF_RESET);
1110         const char *set = diff_get_color(data->color_diff, DIFF_FILE_NEW);
1111         char *err;
1112
1113         if (line[0] == '+') {
1114                 data->lineno++;
1115                 data->status = check_and_emit_line(line + 1, len - 1,
1116                     data->ws_rule, NULL, NULL, NULL, NULL);
1117                 if (!data->status)
1118                         return;
1119                 err = whitespace_error_string(data->status);
1120                 fprintf(data->file, "%s:%d: %s.\n", data->filename, data->lineno, err);
1121                 free(err);
1122                 emit_line(data->file, set, reset, line, 1);
1123                 (void)check_and_emit_line(line + 1, len - 1, data->ws_rule,
1124                     data->file, set, reset, ws);
1125         } else if (line[0] == ' ')
1126                 data->lineno++;
1127         else if (line[0] == '@') {
1128                 char *plus = strchr(line, '+');
1129                 if (plus)
1130                         data->lineno = strtol(plus, NULL, 10) - 1;
1131                 else
1132                         die("invalid diff");
1133         }
1134 }
1135
1136 static unsigned char *deflate_it(char *data,
1137                                  unsigned long size,
1138                                  unsigned long *result_size)
1139 {
1140         int bound;
1141         unsigned char *deflated;
1142         z_stream stream;
1143
1144         memset(&stream, 0, sizeof(stream));
1145         deflateInit(&stream, zlib_compression_level);
1146         bound = deflateBound(&stream, size);
1147         deflated = xmalloc(bound);
1148         stream.next_out = deflated;
1149         stream.avail_out = bound;
1150
1151         stream.next_in = (unsigned char *)data;
1152         stream.avail_in = size;
1153         while (deflate(&stream, Z_FINISH) == Z_OK)
1154                 ; /* nothing */
1155         deflateEnd(&stream);
1156         *result_size = stream.total_out;
1157         return deflated;
1158 }
1159
1160 static void emit_binary_diff_body(FILE *file, mmfile_t *one, mmfile_t *two)
1161 {
1162         void *cp;
1163         void *delta;
1164         void *deflated;
1165         void *data;
1166         unsigned long orig_size;
1167         unsigned long delta_size;
1168         unsigned long deflate_size;
1169         unsigned long data_size;
1170
1171         /* We could do deflated delta, or we could do just deflated two,
1172          * whichever is smaller.
1173          */
1174         delta = NULL;
1175         deflated = deflate_it(two->ptr, two->size, &deflate_size);
1176         if (one->size && two->size) {
1177                 delta = diff_delta(one->ptr, one->size,
1178                                    two->ptr, two->size,
1179                                    &delta_size, deflate_size);
1180                 if (delta) {
1181                         void *to_free = delta;
1182                         orig_size = delta_size;
1183                         delta = deflate_it(delta, delta_size, &delta_size);
1184                         free(to_free);
1185                 }
1186         }
1187
1188         if (delta && delta_size < deflate_size) {
1189                 fprintf(file, "delta %lu\n", orig_size);
1190                 free(deflated);
1191                 data = delta;
1192                 data_size = delta_size;
1193         }
1194         else {
1195                 fprintf(file, "literal %lu\n", two->size);
1196                 free(delta);
1197                 data = deflated;
1198                 data_size = deflate_size;
1199         }
1200
1201         /* emit data encoded in base85 */
1202         cp = data;
1203         while (data_size) {
1204                 int bytes = (52 < data_size) ? 52 : data_size;
1205                 char line[70];
1206                 data_size -= bytes;
1207                 if (bytes <= 26)
1208                         line[0] = bytes + 'A' - 1;
1209                 else
1210                         line[0] = bytes - 26 + 'a' - 1;
1211                 encode_85(line + 1, cp, bytes);
1212                 cp = (char *) cp + bytes;
1213                 fputs(line, file);
1214                 fputc('\n', file);
1215         }
1216         fprintf(file, "\n");
1217         free(data);
1218 }
1219
1220 static void emit_binary_diff(FILE *file, mmfile_t *one, mmfile_t *two)
1221 {
1222         fprintf(file, "GIT binary patch\n");
1223         emit_binary_diff_body(file, one, two);
1224         emit_binary_diff_body(file, two, one);
1225 }
1226
1227 static void setup_diff_attr_check(struct git_attr_check *check)
1228 {
1229         static struct git_attr *attr_diff;
1230
1231         if (!attr_diff) {
1232                 attr_diff = git_attr("diff", 4);
1233         }
1234         check[0].attr = attr_diff;
1235 }
1236
1237 static void diff_filespec_check_attr(struct diff_filespec *one)
1238 {
1239         struct git_attr_check attr_diff_check;
1240         int check_from_data = 0;
1241
1242         if (one->checked_attr)
1243                 return;
1244
1245         setup_diff_attr_check(&attr_diff_check);
1246         one->is_binary = 0;
1247         one->funcname_pattern_ident = NULL;
1248
1249         if (!git_checkattr(one->path, 1, &attr_diff_check)) {
1250                 const char *value;
1251
1252                 /* binaryness */
1253                 value = attr_diff_check.value;
1254                 if (ATTR_TRUE(value))
1255                         ;
1256                 else if (ATTR_FALSE(value))
1257                         one->is_binary = 1;
1258                 else
1259                         check_from_data = 1;
1260
1261                 /* funcname pattern ident */
1262                 if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
1263                         ;
1264                 else
1265                         one->funcname_pattern_ident = value;
1266         }
1267
1268         if (check_from_data) {
1269                 if (!one->data && DIFF_FILE_VALID(one))
1270                         diff_populate_filespec(one, 0);
1271
1272                 if (one->data)
1273                         one->is_binary = buffer_is_binary(one->data, one->size);
1274         }
1275 }
1276
1277 int diff_filespec_is_binary(struct diff_filespec *one)
1278 {
1279         diff_filespec_check_attr(one);
1280         return one->is_binary;
1281 }
1282
1283 static const char *funcname_pattern(const char *ident)
1284 {
1285         struct funcname_pattern *pp;
1286
1287         for (pp = funcname_pattern_list; pp; pp = pp->next)
1288                 if (!strcmp(ident, pp->name))
1289                         return pp->pattern;
1290         return NULL;
1291 }
1292
1293 static struct builtin_funcname_pattern {
1294         const char *name;
1295         const char *pattern;
1296 } builtin_funcname_pattern[] = {
1297         { "java", "!^[  ]*\\(catch\\|do\\|for\\|if\\|instanceof\\|"
1298                         "new\\|return\\|switch\\|throw\\|while\\)\n"
1299                         "^[     ]*\\(\\([       ]*"
1300                         "[A-Za-z_][A-Za-z_0-9]*\\)\\{2,\\}"
1301                         "[      ]*([^;]*\\)$" },
1302         { "tex", "^\\(\\\\\\(sub\\)*section{.*\\)$" },
1303 };
1304
1305 static const char *diff_funcname_pattern(struct diff_filespec *one)
1306 {
1307         const char *ident, *pattern;
1308         int i;
1309
1310         diff_filespec_check_attr(one);
1311         ident = one->funcname_pattern_ident;
1312
1313         if (!ident)
1314                 /*
1315                  * If the config file has "funcname.default" defined, that
1316                  * regexp is used; otherwise NULL is returned and xemit uses
1317                  * the built-in default.
1318                  */
1319                 return funcname_pattern("default");
1320
1321         /* Look up custom "funcname.$ident" regexp from config. */
1322         pattern = funcname_pattern(ident);
1323         if (pattern)
1324                 return pattern;
1325
1326         /*
1327          * And define built-in fallback patterns here.  Note that
1328          * these can be overridden by the user's config settings.
1329          */
1330         for (i = 0; i < ARRAY_SIZE(builtin_funcname_pattern); i++)
1331                 if (!strcmp(ident, builtin_funcname_pattern[i].name))
1332                         return builtin_funcname_pattern[i].pattern;
1333
1334         return NULL;
1335 }
1336
1337 static void builtin_diff(const char *name_a,
1338                          const char *name_b,
1339                          struct diff_filespec *one,
1340                          struct diff_filespec *two,
1341                          const char *xfrm_msg,
1342                          struct diff_options *o,
1343                          int complete_rewrite)
1344 {
1345         mmfile_t mf1, mf2;
1346         const char *lbl[2];
1347         char *a_one, *b_two;
1348         const char *set = diff_get_color_opt(o, DIFF_METAINFO);
1349         const char *reset = diff_get_color_opt(o, DIFF_RESET);
1350
1351         a_one = quote_two(o->a_prefix, name_a + (*name_a == '/'));
1352         b_two = quote_two(o->b_prefix, name_b + (*name_b == '/'));
1353         lbl[0] = DIFF_FILE_VALID(one) ? a_one : "/dev/null";
1354         lbl[1] = DIFF_FILE_VALID(two) ? b_two : "/dev/null";
1355         fprintf(o->file, "%sdiff --git %s %s%s\n", set, a_one, b_two, reset);
1356         if (lbl[0][0] == '/') {
1357                 /* /dev/null */
1358                 fprintf(o->file, "%snew file mode %06o%s\n", set, two->mode, reset);
1359                 if (xfrm_msg && xfrm_msg[0])
1360                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1361         }
1362         else if (lbl[1][0] == '/') {
1363                 fprintf(o->file, "%sdeleted file mode %06o%s\n", set, one->mode, reset);
1364                 if (xfrm_msg && xfrm_msg[0])
1365                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1366         }
1367         else {
1368                 if (one->mode != two->mode) {
1369                         fprintf(o->file, "%sold mode %06o%s\n", set, one->mode, reset);
1370                         fprintf(o->file, "%snew mode %06o%s\n", set, two->mode, reset);
1371                 }
1372                 if (xfrm_msg && xfrm_msg[0])
1373                         fprintf(o->file, "%s%s%s\n", set, xfrm_msg, reset);
1374                 /*
1375                  * we do not run diff between different kind
1376                  * of objects.
1377                  */
1378                 if ((one->mode ^ two->mode) & S_IFMT)
1379                         goto free_ab_and_return;
1380                 if (complete_rewrite) {
1381                         emit_rewrite_diff(name_a, name_b, one, two, o);
1382                         o->found_changes = 1;
1383                         goto free_ab_and_return;
1384                 }
1385         }
1386
1387         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1388                 die("unable to read files to diff");
1389
1390         if (!DIFF_OPT_TST(o, TEXT) &&
1391             (diff_filespec_is_binary(one) || diff_filespec_is_binary(two))) {
1392                 /* Quite common confusing case */
1393                 if (mf1.size == mf2.size &&
1394                     !memcmp(mf1.ptr, mf2.ptr, mf1.size))
1395                         goto free_ab_and_return;
1396                 if (DIFF_OPT_TST(o, BINARY))
1397                         emit_binary_diff(o->file, &mf1, &mf2);
1398                 else
1399                         fprintf(o->file, "Binary files %s and %s differ\n",
1400                                 lbl[0], lbl[1]);
1401                 o->found_changes = 1;
1402         }
1403         else {
1404                 /* Crazy xdl interfaces.. */
1405                 const char *diffopts = getenv("GIT_DIFF_OPTS");
1406                 xpparam_t xpp;
1407                 xdemitconf_t xecfg;
1408                 xdemitcb_t ecb;
1409                 struct emit_callback ecbdata;
1410                 const char *funcname_pattern;
1411
1412                 funcname_pattern = diff_funcname_pattern(one);
1413                 if (!funcname_pattern)
1414                         funcname_pattern = diff_funcname_pattern(two);
1415
1416                 memset(&xecfg, 0, sizeof(xecfg));
1417                 memset(&ecbdata, 0, sizeof(ecbdata));
1418                 ecbdata.label_path = lbl;
1419                 ecbdata.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1420                 ecbdata.found_changesp = &o->found_changes;
1421                 ecbdata.ws_rule = whitespace_rule(name_b ? name_b : name_a);
1422                 ecbdata.file = o->file;
1423                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1424                 xecfg.ctxlen = o->context;
1425                 xecfg.flags = XDL_EMIT_FUNCNAMES;
1426                 if (funcname_pattern)
1427                         xdiff_set_find_func(&xecfg, funcname_pattern);
1428                 if (!diffopts)
1429                         ;
1430                 else if (!prefixcmp(diffopts, "--unified="))
1431                         xecfg.ctxlen = strtoul(diffopts + 10, NULL, 10);
1432                 else if (!prefixcmp(diffopts, "-u"))
1433                         xecfg.ctxlen = strtoul(diffopts + 2, NULL, 10);
1434                 ecb.outf = xdiff_outf;
1435                 ecb.priv = &ecbdata;
1436                 ecbdata.xm.consume = fn_out_consume;
1437                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS)) {
1438                         ecbdata.diff_words =
1439                                 xcalloc(1, sizeof(struct diff_words_data));
1440                         ecbdata.diff_words->file = o->file;
1441                 }
1442                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1443                 if (DIFF_OPT_TST(o, COLOR_DIFF_WORDS))
1444                         free_diff_words_data(&ecbdata);
1445         }
1446
1447  free_ab_and_return:
1448         diff_free_filespec_data(one);
1449         diff_free_filespec_data(two);
1450         free(a_one);
1451         free(b_two);
1452         return;
1453 }
1454
1455 static void builtin_diffstat(const char *name_a, const char *name_b,
1456                              struct diff_filespec *one,
1457                              struct diff_filespec *two,
1458                              struct diffstat_t *diffstat,
1459                              struct diff_options *o,
1460                              int complete_rewrite)
1461 {
1462         mmfile_t mf1, mf2;
1463         struct diffstat_file *data;
1464
1465         data = diffstat_add(diffstat, name_a, name_b);
1466
1467         if (!one || !two) {
1468                 data->is_unmerged = 1;
1469                 return;
1470         }
1471         if (complete_rewrite) {
1472                 diff_populate_filespec(one, 0);
1473                 diff_populate_filespec(two, 0);
1474                 data->deleted = count_lines(one->data, one->size);
1475                 data->added = count_lines(two->data, two->size);
1476                 goto free_and_return;
1477         }
1478         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1479                 die("unable to read files to diff");
1480
1481         if (diff_filespec_is_binary(one) || diff_filespec_is_binary(two)) {
1482                 data->is_binary = 1;
1483                 data->added = mf2.size;
1484                 data->deleted = mf1.size;
1485         } else {
1486                 /* Crazy xdl interfaces.. */
1487                 xpparam_t xpp;
1488                 xdemitconf_t xecfg;
1489                 xdemitcb_t ecb;
1490
1491                 memset(&xecfg, 0, sizeof(xecfg));
1492                 xpp.flags = XDF_NEED_MINIMAL | o->xdl_opts;
1493                 ecb.outf = xdiff_outf;
1494                 ecb.priv = diffstat;
1495                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1496         }
1497
1498  free_and_return:
1499         diff_free_filespec_data(one);
1500         diff_free_filespec_data(two);
1501 }
1502
1503 static void builtin_checkdiff(const char *name_a, const char *name_b,
1504                               const char *attr_path,
1505                              struct diff_filespec *one,
1506                              struct diff_filespec *two, struct diff_options *o)
1507 {
1508         mmfile_t mf1, mf2;
1509         struct checkdiff_t data;
1510
1511         if (!two)
1512                 return;
1513
1514         memset(&data, 0, sizeof(data));
1515         data.xm.consume = checkdiff_consume;
1516         data.filename = name_b ? name_b : name_a;
1517         data.lineno = 0;
1518         data.color_diff = DIFF_OPT_TST(o, COLOR_DIFF);
1519         data.ws_rule = whitespace_rule(attr_path);
1520         data.file = o->file;
1521
1522         if (fill_mmfile(&mf1, one) < 0 || fill_mmfile(&mf2, two) < 0)
1523                 die("unable to read files to diff");
1524
1525         if (diff_filespec_is_binary(two))
1526                 goto free_and_return;
1527         else {
1528                 /* Crazy xdl interfaces.. */
1529                 xpparam_t xpp;
1530                 xdemitconf_t xecfg;
1531                 xdemitcb_t ecb;
1532
1533                 memset(&xecfg, 0, sizeof(xecfg));
1534                 xpp.flags = XDF_NEED_MINIMAL;
1535                 ecb.outf = xdiff_outf;
1536                 ecb.priv = &data;
1537                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
1538         }
1539  free_and_return:
1540         diff_free_filespec_data(one);
1541         diff_free_filespec_data(two);
1542         if (data.status)
1543                 DIFF_OPT_SET(o, CHECK_FAILED);
1544 }
1545
1546 struct diff_filespec *alloc_filespec(const char *path)
1547 {
1548         int namelen = strlen(path);
1549         struct diff_filespec *spec = xmalloc(sizeof(*spec) + namelen + 1);
1550
1551         memset(spec, 0, sizeof(*spec));
1552         spec->path = (char *)(spec + 1);
1553         memcpy(spec->path, path, namelen+1);
1554         spec->count = 1;
1555         return spec;
1556 }
1557
1558 void free_filespec(struct diff_filespec *spec)
1559 {
1560         if (!--spec->count) {
1561                 diff_free_filespec_data(spec);
1562                 free(spec);
1563         }
1564 }
1565
1566 void fill_filespec(struct diff_filespec *spec, const unsigned char *sha1,
1567                    unsigned short mode)
1568 {
1569         if (mode) {
1570                 spec->mode = canon_mode(mode);
1571                 hashcpy(spec->sha1, sha1);
1572                 spec->sha1_valid = !is_null_sha1(sha1);
1573         }
1574 }
1575
1576 /*
1577  * Given a name and sha1 pair, if the index tells us the file in
1578  * the work tree has that object contents, return true, so that
1579  * prepare_temp_file() does not have to inflate and extract.
1580  */
1581 static int reuse_worktree_file(const char *name, const unsigned char *sha1, int want_file)
1582 {
1583         struct cache_entry *ce;
1584         struct stat st;
1585         int pos, len;
1586
1587         /* We do not read the cache ourselves here, because the
1588          * benchmark with my previous version that always reads cache
1589          * shows that it makes things worse for diff-tree comparing
1590          * two linux-2.6 kernel trees in an already checked out work
1591          * tree.  This is because most diff-tree comparisons deal with
1592          * only a small number of files, while reading the cache is
1593          * expensive for a large project, and its cost outweighs the
1594          * savings we get by not inflating the object to a temporary
1595          * file.  Practically, this code only helps when we are used
1596          * by diff-cache --cached, which does read the cache before
1597          * calling us.
1598          */
1599         if (!active_cache)
1600                 return 0;
1601
1602         /* We want to avoid the working directory if our caller
1603          * doesn't need the data in a normal file, this system
1604          * is rather slow with its stat/open/mmap/close syscalls,
1605          * and the object is contained in a pack file.  The pack
1606          * is probably already open and will be faster to obtain
1607          * the data through than the working directory.  Loose
1608          * objects however would tend to be slower as they need
1609          * to be individually opened and inflated.
1610          */
1611         if (!FAST_WORKING_DIRECTORY && !want_file && has_sha1_pack(sha1, NULL))
1612                 return 0;
1613
1614         len = strlen(name);
1615         pos = cache_name_pos(name, len);
1616         if (pos < 0)
1617                 return 0;
1618         ce = active_cache[pos];
1619
1620         /*
1621          * This is not the sha1 we are looking for, or
1622          * unreusable because it is not a regular file.
1623          */
1624         if (hashcmp(sha1, ce->sha1) || !S_ISREG(ce->ce_mode))
1625                 return 0;
1626
1627         /*
1628          * If ce matches the file in the work tree, we can reuse it.
1629          */
1630         if (ce_uptodate(ce) ||
1631             (!lstat(name, &st) && !ce_match_stat(ce, &st, 0)))
1632                 return 1;
1633
1634         return 0;
1635 }
1636
1637 static int populate_from_stdin(struct diff_filespec *s)
1638 {
1639         struct strbuf buf;
1640         size_t size = 0;
1641
1642         strbuf_init(&buf, 0);
1643         if (strbuf_read(&buf, 0, 0) < 0)
1644                 return error("error while reading from stdin %s",
1645                                      strerror(errno));
1646
1647         s->should_munmap = 0;
1648         s->data = strbuf_detach(&buf, &size);
1649         s->size = size;
1650         s->should_free = 1;
1651         return 0;
1652 }
1653
1654 static int diff_populate_gitlink(struct diff_filespec *s, int size_only)
1655 {
1656         int len;
1657         char *data = xmalloc(100);
1658         len = snprintf(data, 100,
1659                 "Subproject commit %s\n", sha1_to_hex(s->sha1));
1660         s->data = data;
1661         s->size = len;
1662         s->should_free = 1;
1663         if (size_only) {
1664                 s->data = NULL;
1665                 free(data);
1666         }
1667         return 0;
1668 }
1669
1670 /*
1671  * While doing rename detection and pickaxe operation, we may need to
1672  * grab the data for the blob (or file) for our own in-core comparison.
1673  * diff_filespec has data and size fields for this purpose.
1674  */
1675 int diff_populate_filespec(struct diff_filespec *s, int size_only)
1676 {
1677         int err = 0;
1678         if (!DIFF_FILE_VALID(s))
1679                 die("internal error: asking to populate invalid file.");
1680         if (S_ISDIR(s->mode))
1681                 return -1;
1682
1683         if (s->data)
1684                 return 0;
1685
1686         if (size_only && 0 < s->size)
1687                 return 0;
1688
1689         if (S_ISGITLINK(s->mode))
1690                 return diff_populate_gitlink(s, size_only);
1691
1692         if (!s->sha1_valid ||
1693             reuse_worktree_file(s->path, s->sha1, 0)) {
1694                 struct strbuf buf;
1695                 struct stat st;
1696                 int fd;
1697
1698                 if (!strcmp(s->path, "-"))
1699                         return populate_from_stdin(s);
1700
1701                 if (lstat(s->path, &st) < 0) {
1702                         if (errno == ENOENT) {
1703                         err_empty:
1704                                 err = -1;
1705                         empty:
1706                                 s->data = (char *)"";
1707                                 s->size = 0;
1708                                 return err;
1709                         }
1710                 }
1711                 s->size = xsize_t(st.st_size);
1712                 if (!s->size)
1713                         goto empty;
1714                 if (size_only)
1715                         return 0;
1716                 if (S_ISLNK(st.st_mode)) {
1717                         int ret;
1718                         s->data = xmalloc(s->size);
1719                         s->should_free = 1;
1720                         ret = readlink(s->path, s->data, s->size);
1721                         if (ret < 0) {
1722                                 free(s->data);
1723                                 goto err_empty;
1724                         }
1725                         return 0;
1726                 }
1727                 fd = open(s->path, O_RDONLY);
1728                 if (fd < 0)
1729                         goto err_empty;
1730                 s->data = xmmap(NULL, s->size, PROT_READ, MAP_PRIVATE, fd, 0);
1731                 close(fd);
1732                 s->should_munmap = 1;
1733
1734                 /*
1735                  * Convert from working tree format to canonical git format
1736                  */
1737                 strbuf_init(&buf, 0);
1738                 if (convert_to_git(s->path, s->data, s->size, &buf, safe_crlf)) {
1739                         size_t size = 0;
1740                         munmap(s->data, s->size);
1741                         s->should_munmap = 0;
1742                         s->data = strbuf_detach(&buf, &size);
1743                         s->size = size;
1744                         s->should_free = 1;
1745                 }
1746         }
1747         else {
1748                 enum object_type type;
1749                 if (size_only)
1750                         type = sha1_object_info(s->sha1, &s->size);
1751                 else {
1752                         s->data = read_sha1_file(s->sha1, &type, &s->size);
1753                         s->should_free = 1;
1754                 }
1755         }
1756         return 0;
1757 }
1758
1759 void diff_free_filespec_blob(struct diff_filespec *s)
1760 {
1761         if (s->should_free)
1762                 free(s->data);
1763         else if (s->should_munmap)
1764                 munmap(s->data, s->size);
1765
1766         if (s->should_free || s->should_munmap) {
1767                 s->should_free = s->should_munmap = 0;
1768                 s->data = NULL;
1769         }
1770 }
1771
1772 void diff_free_filespec_data(struct diff_filespec *s)
1773 {
1774         diff_free_filespec_blob(s);
1775         free(s->cnt_data);
1776         s->cnt_data = NULL;
1777 }
1778
1779 static void prep_temp_blob(struct diff_tempfile *temp,
1780                            void *blob,
1781                            unsigned long size,
1782                            const unsigned char *sha1,
1783                            int mode)
1784 {
1785         int fd;
1786
1787         fd = git_mkstemp(temp->tmp_path, PATH_MAX, ".diff_XXXXXX");
1788         if (fd < 0)
1789                 die("unable to create temp-file: %s", strerror(errno));
1790         if (write_in_full(fd, blob, size) != size)
1791                 die("unable to write temp-file");
1792         close(fd);
1793         temp->name = temp->tmp_path;
1794         strcpy(temp->hex, sha1_to_hex(sha1));
1795         temp->hex[40] = 0;
1796         sprintf(temp->mode, "%06o", mode);
1797 }
1798
1799 static void prepare_temp_file(const char *name,
1800                               struct diff_tempfile *temp,
1801                               struct diff_filespec *one)
1802 {
1803         if (!DIFF_FILE_VALID(one)) {
1804         not_a_valid_file:
1805                 /* A '-' entry produces this for file-2, and
1806                  * a '+' entry produces this for file-1.
1807                  */
1808                 temp->name = "/dev/null";
1809                 strcpy(temp->hex, ".");
1810                 strcpy(temp->mode, ".");
1811                 return;
1812         }
1813
1814         if (!one->sha1_valid ||
1815             reuse_worktree_file(name, one->sha1, 1)) {
1816                 struct stat st;
1817                 if (lstat(name, &st) < 0) {
1818                         if (errno == ENOENT)
1819                                 goto not_a_valid_file;
1820                         die("stat(%s): %s", name, strerror(errno));
1821                 }
1822                 if (S_ISLNK(st.st_mode)) {
1823                         int ret;
1824                         char buf[PATH_MAX + 1]; /* ought to be SYMLINK_MAX */
1825                         size_t sz = xsize_t(st.st_size);
1826                         if (sizeof(buf) <= st.st_size)
1827                                 die("symlink too long: %s", name);
1828                         ret = readlink(name, buf, sz);
1829                         if (ret < 0)
1830                                 die("readlink(%s)", name);
1831                         prep_temp_blob(temp, buf, sz,
1832                                        (one->sha1_valid ?
1833                                         one->sha1 : null_sha1),
1834                                        (one->sha1_valid ?
1835                                         one->mode : S_IFLNK));
1836                 }
1837                 else {
1838                         /* we can borrow from the file in the work tree */
1839                         temp->name = name;
1840                         if (!one->sha1_valid)
1841                                 strcpy(temp->hex, sha1_to_hex(null_sha1));
1842                         else
1843                                 strcpy(temp->hex, sha1_to_hex(one->sha1));
1844                         /* Even though we may sometimes borrow the
1845                          * contents from the work tree, we always want
1846                          * one->mode.  mode is trustworthy even when
1847                          * !(one->sha1_valid), as long as
1848                          * DIFF_FILE_VALID(one).
1849                          */
1850                         sprintf(temp->mode, "%06o", one->mode);
1851                 }
1852                 return;
1853         }
1854         else {
1855                 if (diff_populate_filespec(one, 0))
1856                         die("cannot read data blob for %s", one->path);
1857                 prep_temp_blob(temp, one->data, one->size,
1858                                one->sha1, one->mode);
1859         }
1860 }
1861
1862 static void remove_tempfile(void)
1863 {
1864         int i;
1865
1866         for (i = 0; i < 2; i++)
1867                 if (diff_temp[i].name == diff_temp[i].tmp_path) {
1868                         unlink(diff_temp[i].name);
1869                         diff_temp[i].name = NULL;
1870                 }
1871 }
1872
1873 static void remove_tempfile_on_signal(int signo)
1874 {
1875         remove_tempfile();
1876         signal(SIGINT, SIG_DFL);
1877         raise(signo);
1878 }
1879
1880 /* An external diff command takes:
1881  *
1882  * diff-cmd name infile1 infile1-sha1 infile1-mode \
1883  *               infile2 infile2-sha1 infile2-mode [ rename-to ]
1884  *
1885  */
1886 static void run_external_diff(const char *pgm,
1887                               const char *name,
1888                               const char *other,
1889                               struct diff_filespec *one,
1890                               struct diff_filespec *two,
1891                               const char *xfrm_msg,
1892                               int complete_rewrite)
1893 {
1894         const char *spawn_arg[10];
1895         struct diff_tempfile *temp = diff_temp;
1896         int retval;
1897         static int atexit_asked = 0;
1898         const char *othername;
1899         const char **arg = &spawn_arg[0];
1900
1901         othername = (other? other : name);
1902         if (one && two) {
1903                 prepare_temp_file(name, &temp[0], one);
1904                 prepare_temp_file(othername, &temp[1], two);
1905                 if (! atexit_asked &&
1906                     (temp[0].name == temp[0].tmp_path ||
1907                      temp[1].name == temp[1].tmp_path)) {
1908                         atexit_asked = 1;
1909                         atexit(remove_tempfile);
1910                 }
1911                 signal(SIGINT, remove_tempfile_on_signal);
1912         }
1913
1914         if (one && two) {
1915                 *arg++ = pgm;
1916                 *arg++ = name;
1917                 *arg++ = temp[0].name;
1918                 *arg++ = temp[0].hex;
1919                 *arg++ = temp[0].mode;
1920                 *arg++ = temp[1].name;
1921                 *arg++ = temp[1].hex;
1922                 *arg++ = temp[1].mode;
1923                 if (other) {
1924                         *arg++ = other;
1925                         *arg++ = xfrm_msg;
1926                 }
1927         } else {
1928                 *arg++ = pgm;
1929                 *arg++ = name;
1930         }
1931         *arg = NULL;
1932         fflush(NULL);
1933         retval = run_command_v_opt(spawn_arg, 0);
1934         remove_tempfile();
1935         if (retval) {
1936                 fprintf(stderr, "external diff died, stopping at %s.\n", name);
1937                 exit(1);
1938         }
1939 }
1940
1941 static const char *external_diff_attr(const char *name)
1942 {
1943         struct git_attr_check attr_diff_check;
1944
1945         if (!name)
1946                 return NULL;
1947
1948         setup_diff_attr_check(&attr_diff_check);
1949         if (!git_checkattr(name, 1, &attr_diff_check)) {
1950                 const char *value = attr_diff_check.value;
1951                 if (!ATTR_TRUE(value) &&
1952                     !ATTR_FALSE(value) &&
1953                     !ATTR_UNSET(value)) {
1954                         struct ll_diff_driver *drv;
1955
1956                         for (drv = user_diff; drv; drv = drv->next)
1957                                 if (!strcmp(drv->name, value))
1958                                         return drv->cmd;
1959                 }
1960         }
1961         return NULL;
1962 }
1963
1964 static void run_diff_cmd(const char *pgm,
1965                          const char *name,
1966                          const char *other,
1967                          const char *attr_path,
1968                          struct diff_filespec *one,
1969                          struct diff_filespec *two,
1970                          const char *xfrm_msg,
1971                          struct diff_options *o,
1972                          int complete_rewrite)
1973 {
1974         if (!DIFF_OPT_TST(o, ALLOW_EXTERNAL))
1975                 pgm = NULL;
1976         else {
1977                 const char *cmd = external_diff_attr(attr_path);
1978                 if (cmd)
1979                         pgm = cmd;
1980         }
1981
1982         if (pgm) {
1983                 run_external_diff(pgm, name, other, one, two, xfrm_msg,
1984                                   complete_rewrite);
1985                 return;
1986         }
1987         if (one && two)
1988                 builtin_diff(name, other ? other : name,
1989                              one, two, xfrm_msg, o, complete_rewrite);
1990         else
1991                 fprintf(o->file, "* Unmerged path %s\n", name);
1992 }
1993
1994 static void diff_fill_sha1_info(struct diff_filespec *one)
1995 {
1996         if (DIFF_FILE_VALID(one)) {
1997                 if (!one->sha1_valid) {
1998                         struct stat st;
1999                         if (!strcmp(one->path, "-")) {
2000                                 hashcpy(one->sha1, null_sha1);
2001                                 return;
2002                         }
2003                         if (lstat(one->path, &st) < 0)
2004                                 die("stat %s", one->path);
2005                         if (index_path(one->sha1, one->path, &st, 0))
2006                                 die("cannot hash %s\n", one->path);
2007                 }
2008         }
2009         else
2010                 hashclr(one->sha1);
2011 }
2012
2013 static int similarity_index(struct diff_filepair *p)
2014 {
2015         return p->score * 100 / MAX_SCORE;
2016 }
2017
2018 static void strip_prefix(int prefix_length, const char **namep, const char **otherp)
2019 {
2020         /* Strip the prefix but do not molest /dev/null and absolute paths */
2021         if (*namep && **namep != '/')
2022                 *namep += prefix_length;
2023         if (*otherp && **otherp != '/')
2024                 *otherp += prefix_length;
2025 }
2026
2027 static void run_diff(struct diff_filepair *p, struct diff_options *o)
2028 {
2029         const char *pgm = external_diff();
2030         struct strbuf msg;
2031         char *xfrm_msg;
2032         struct diff_filespec *one = p->one;
2033         struct diff_filespec *two = p->two;
2034         const char *name;
2035         const char *other;
2036         const char *attr_path;
2037         int complete_rewrite = 0;
2038
2039         name  = p->one->path;
2040         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2041         attr_path = name;
2042         if (o->prefix_length)
2043                 strip_prefix(o->prefix_length, &name, &other);
2044
2045         if (DIFF_PAIR_UNMERGED(p)) {
2046                 run_diff_cmd(pgm, name, NULL, attr_path,
2047                              NULL, NULL, NULL, o, 0);
2048                 return;
2049         }
2050
2051         diff_fill_sha1_info(one);
2052         diff_fill_sha1_info(two);
2053
2054         strbuf_init(&msg, PATH_MAX * 2 + 300);
2055         switch (p->status) {
2056         case DIFF_STATUS_COPIED:
2057                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2058                 strbuf_addstr(&msg, "\ncopy from ");
2059                 quote_c_style(name, &msg, NULL, 0);
2060                 strbuf_addstr(&msg, "\ncopy to ");
2061                 quote_c_style(other, &msg, NULL, 0);
2062                 strbuf_addch(&msg, '\n');
2063                 break;
2064         case DIFF_STATUS_RENAMED:
2065                 strbuf_addf(&msg, "similarity index %d%%", similarity_index(p));
2066                 strbuf_addstr(&msg, "\nrename from ");
2067                 quote_c_style(name, &msg, NULL, 0);
2068                 strbuf_addstr(&msg, "\nrename to ");
2069                 quote_c_style(other, &msg, NULL, 0);
2070                 strbuf_addch(&msg, '\n');
2071                 break;
2072         case DIFF_STATUS_MODIFIED:
2073                 if (p->score) {
2074                         strbuf_addf(&msg, "dissimilarity index %d%%\n",
2075                                         similarity_index(p));
2076                         complete_rewrite = 1;
2077                         break;
2078                 }
2079                 /* fallthru */
2080         default:
2081                 /* nothing */
2082                 ;
2083         }
2084
2085         if (hashcmp(one->sha1, two->sha1)) {
2086                 int abbrev = DIFF_OPT_TST(o, FULL_INDEX) ? 40 : DEFAULT_ABBREV;
2087
2088                 if (DIFF_OPT_TST(o, BINARY)) {
2089                         mmfile_t mf;
2090                         if ((!fill_mmfile(&mf, one) && diff_filespec_is_binary(one)) ||
2091                             (!fill_mmfile(&mf, two) && diff_filespec_is_binary(two)))
2092                                 abbrev = 40;
2093                 }
2094                 strbuf_addf(&msg, "index %.*s..%.*s",
2095                                 abbrev, sha1_to_hex(one->sha1),
2096                                 abbrev, sha1_to_hex(two->sha1));
2097                 if (one->mode == two->mode)
2098                         strbuf_addf(&msg, " %06o", one->mode);
2099                 strbuf_addch(&msg, '\n');
2100         }
2101
2102         if (msg.len)
2103                 strbuf_setlen(&msg, msg.len - 1);
2104         xfrm_msg = msg.len ? msg.buf : NULL;
2105
2106         if (!pgm &&
2107             DIFF_FILE_VALID(one) && DIFF_FILE_VALID(two) &&
2108             (S_IFMT & one->mode) != (S_IFMT & two->mode)) {
2109                 /* a filepair that changes between file and symlink
2110                  * needs to be split into deletion and creation.
2111                  */
2112                 struct diff_filespec *null = alloc_filespec(two->path);
2113                 run_diff_cmd(NULL, name, other, attr_path,
2114                              one, null, xfrm_msg, o, 0);
2115                 free(null);
2116                 null = alloc_filespec(one->path);
2117                 run_diff_cmd(NULL, name, other, attr_path,
2118                              null, two, xfrm_msg, o, 0);
2119                 free(null);
2120         }
2121         else
2122                 run_diff_cmd(pgm, name, other, attr_path,
2123                              one, two, xfrm_msg, o, complete_rewrite);
2124
2125         strbuf_release(&msg);
2126 }
2127
2128 static void run_diffstat(struct diff_filepair *p, struct diff_options *o,
2129                          struct diffstat_t *diffstat)
2130 {
2131         const char *name;
2132         const char *other;
2133         int complete_rewrite = 0;
2134
2135         if (DIFF_PAIR_UNMERGED(p)) {
2136                 /* unmerged */
2137                 builtin_diffstat(p->one->path, NULL, NULL, NULL, diffstat, o, 0);
2138                 return;
2139         }
2140
2141         name = p->one->path;
2142         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2143
2144         if (o->prefix_length)
2145                 strip_prefix(o->prefix_length, &name, &other);
2146
2147         diff_fill_sha1_info(p->one);
2148         diff_fill_sha1_info(p->two);
2149
2150         if (p->status == DIFF_STATUS_MODIFIED && p->score)
2151                 complete_rewrite = 1;
2152         builtin_diffstat(name, other, p->one, p->two, diffstat, o, complete_rewrite);
2153 }
2154
2155 static void run_checkdiff(struct diff_filepair *p, struct diff_options *o)
2156 {
2157         const char *name;
2158         const char *other;
2159         const char *attr_path;
2160
2161         if (DIFF_PAIR_UNMERGED(p)) {
2162                 /* unmerged */
2163                 return;
2164         }
2165
2166         name = p->one->path;
2167         other = (strcmp(name, p->two->path) ? p->two->path : NULL);
2168         attr_path = other ? other : name;
2169
2170         if (o->prefix_length)
2171                 strip_prefix(o->prefix_length, &name, &other);
2172
2173         diff_fill_sha1_info(p->one);
2174         diff_fill_sha1_info(p->two);
2175
2176         builtin_checkdiff(name, other, attr_path, p->one, p->two, o);
2177 }
2178
2179 void diff_setup(struct diff_options *options)
2180 {
2181         memset(options, 0, sizeof(*options));
2182
2183         options->file = stdout;
2184
2185         options->line_termination = '\n';
2186         options->break_opt = -1;
2187         options->rename_limit = -1;
2188         options->dirstat_percent = 3;
2189         options->context = 3;
2190         options->msg_sep = "";
2191
2192         options->change = diff_change;
2193         options->add_remove = diff_addremove;
2194         if (diff_use_color_default > 0)
2195                 DIFF_OPT_SET(options, COLOR_DIFF);
2196         else
2197                 DIFF_OPT_CLR(options, COLOR_DIFF);
2198         options->detect_rename = diff_detect_rename_default;
2199
2200         options->a_prefix = "a/";
2201         options->b_prefix = "b/";
2202 }
2203
2204 int diff_setup_done(struct diff_options *options)
2205 {
2206         int count = 0;
2207
2208         if (options->output_format & DIFF_FORMAT_NAME)
2209                 count++;
2210         if (options->output_format & DIFF_FORMAT_NAME_STATUS)
2211                 count++;
2212         if (options->output_format & DIFF_FORMAT_CHECKDIFF)
2213                 count++;
2214         if (options->output_format & DIFF_FORMAT_NO_OUTPUT)
2215                 count++;
2216         if (count > 1)
2217                 die("--name-only, --name-status, --check and -s are mutually exclusive");
2218
2219         if (DIFF_OPT_TST(options, FIND_COPIES_HARDER))
2220                 options->detect_rename = DIFF_DETECT_COPY;
2221
2222         if (!DIFF_OPT_TST(options, RELATIVE_NAME))
2223                 options->prefix = NULL;
2224         if (options->prefix)
2225                 options->prefix_length = strlen(options->prefix);
2226         else
2227                 options->prefix_length = 0;
2228
2229         if (options->output_format & (DIFF_FORMAT_NAME |
2230                                       DIFF_FORMAT_NAME_STATUS |
2231                                       DIFF_FORMAT_CHECKDIFF |
2232                                       DIFF_FORMAT_NO_OUTPUT))
2233                 options->output_format &= ~(DIFF_FORMAT_RAW |
2234                                             DIFF_FORMAT_NUMSTAT |
2235                                             DIFF_FORMAT_DIFFSTAT |
2236                                             DIFF_FORMAT_SHORTSTAT |
2237                                             DIFF_FORMAT_DIRSTAT |
2238                                             DIFF_FORMAT_SUMMARY |
2239                                             DIFF_FORMAT_PATCH);
2240
2241         /*
2242          * These cases always need recursive; we do not drop caller-supplied
2243          * recursive bits for other formats here.
2244          */
2245         if (options->output_format & (DIFF_FORMAT_PATCH |
2246                                       DIFF_FORMAT_NUMSTAT |
2247                                       DIFF_FORMAT_DIFFSTAT |
2248                                       DIFF_FORMAT_SHORTSTAT |
2249                                       DIFF_FORMAT_DIRSTAT |
2250                                       DIFF_FORMAT_SUMMARY |
2251                                       DIFF_FORMAT_CHECKDIFF))
2252                 DIFF_OPT_SET(options, RECURSIVE);
2253         /*
2254          * Also pickaxe would not work very well if you do not say recursive
2255          */
2256         if (options->pickaxe)
2257                 DIFF_OPT_SET(options, RECURSIVE);
2258
2259         if (options->detect_rename && options->rename_limit < 0)
2260                 options->rename_limit = diff_rename_limit_default;
2261         if (options->setup & DIFF_SETUP_USE_CACHE) {
2262                 if (!active_cache)
2263                         /* read-cache does not die even when it fails
2264                          * so it is safe for us to do this here.  Also
2265                          * it does not smudge active_cache or active_nr
2266                          * when it fails, so we do not have to worry about
2267                          * cleaning it up ourselves either.
2268                          */
2269                         read_cache();
2270         }
2271         if (options->abbrev <= 0 || 40 < options->abbrev)
2272                 options->abbrev = 40; /* full */
2273
2274         /*
2275          * It does not make sense to show the first hit we happened
2276          * to have found.  It does not make sense not to return with
2277          * exit code in such a case either.
2278          */
2279         if (DIFF_OPT_TST(options, QUIET)) {
2280                 options->output_format = DIFF_FORMAT_NO_OUTPUT;
2281                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2282         }
2283
2284         /*
2285          * If we postprocess in diffcore, we cannot simply return
2286          * upon the first hit.  We need to run diff as usual.
2287          */
2288         if (options->pickaxe || options->filter)
2289                 DIFF_OPT_CLR(options, QUIET);
2290
2291         return 0;
2292 }
2293
2294 static int opt_arg(const char *arg, int arg_short, const char *arg_long, int *val)
2295 {
2296         char c, *eq;
2297         int len;
2298
2299         if (*arg != '-')
2300                 return 0;
2301         c = *++arg;
2302         if (!c)
2303                 return 0;
2304         if (c == arg_short) {
2305                 c = *++arg;
2306                 if (!c)
2307                         return 1;
2308                 if (val && isdigit(c)) {
2309                         char *end;
2310                         int n = strtoul(arg, &end, 10);
2311                         if (*end)
2312                                 return 0;
2313                         *val = n;
2314                         return 1;
2315                 }
2316                 return 0;
2317         }
2318         if (c != '-')
2319                 return 0;
2320         arg++;
2321         eq = strchr(arg, '=');
2322         if (eq)
2323                 len = eq - arg;
2324         else
2325                 len = strlen(arg);
2326         if (!len || strncmp(arg, arg_long, len))
2327                 return 0;
2328         if (eq) {
2329                 int n;
2330                 char *end;
2331                 if (!isdigit(*++eq))
2332                         return 0;
2333                 n = strtoul(eq, &end, 10);
2334                 if (*end)
2335                         return 0;
2336                 *val = n;
2337         }
2338         return 1;
2339 }
2340
2341 static int diff_scoreopt_parse(const char *opt);
2342
2343 int diff_opt_parse(struct diff_options *options, const char **av, int ac)
2344 {
2345         const char *arg = av[0];
2346
2347         /* Output format options */
2348         if (!strcmp(arg, "-p") || !strcmp(arg, "-u"))
2349                 options->output_format |= DIFF_FORMAT_PATCH;
2350         else if (opt_arg(arg, 'U', "unified", &options->context))
2351                 options->output_format |= DIFF_FORMAT_PATCH;
2352         else if (!strcmp(arg, "--raw"))
2353                 options->output_format |= DIFF_FORMAT_RAW;
2354         else if (!strcmp(arg, "--patch-with-raw"))
2355                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_RAW;
2356         else if (!strcmp(arg, "--numstat"))
2357                 options->output_format |= DIFF_FORMAT_NUMSTAT;
2358         else if (!strcmp(arg, "--shortstat"))
2359                 options->output_format |= DIFF_FORMAT_SHORTSTAT;
2360         else if (opt_arg(arg, 'X', "dirstat", &options->dirstat_percent))
2361                 options->output_format |= DIFF_FORMAT_DIRSTAT;
2362         else if (!strcmp(arg, "--cumulative"))
2363                 options->output_format |= DIFF_FORMAT_CUMULATIVE;
2364         else if (!strcmp(arg, "--check"))
2365                 options->output_format |= DIFF_FORMAT_CHECKDIFF;
2366         else if (!strcmp(arg, "--summary"))
2367                 options->output_format |= DIFF_FORMAT_SUMMARY;
2368         else if (!strcmp(arg, "--patch-with-stat"))
2369                 options->output_format |= DIFF_FORMAT_PATCH | DIFF_FORMAT_DIFFSTAT;
2370         else if (!strcmp(arg, "--name-only"))
2371                 options->output_format |= DIFF_FORMAT_NAME;
2372         else if (!strcmp(arg, "--name-status"))
2373                 options->output_format |= DIFF_FORMAT_NAME_STATUS;
2374         else if (!strcmp(arg, "-s"))
2375                 options->output_format |= DIFF_FORMAT_NO_OUTPUT;
2376         else if (!prefixcmp(arg, "--stat")) {
2377                 char *end;
2378                 int width = options->stat_width;
2379                 int name_width = options->stat_name_width;
2380                 arg += 6;
2381                 end = (char *)arg;
2382
2383                 switch (*arg) {
2384                 case '-':
2385                         if (!prefixcmp(arg, "-width="))
2386                                 width = strtoul(arg + 7, &end, 10);
2387                         else if (!prefixcmp(arg, "-name-width="))
2388                                 name_width = strtoul(arg + 12, &end, 10);
2389                         break;
2390                 case '=':
2391                         width = strtoul(arg+1, &end, 10);
2392                         if (*end == ',')
2393                                 name_width = strtoul(end+1, &end, 10);
2394                 }
2395
2396                 /* Important! This checks all the error cases! */
2397                 if (*end)
2398                         return 0;
2399                 options->output_format |= DIFF_FORMAT_DIFFSTAT;
2400                 options->stat_name_width = name_width;
2401                 options->stat_width = width;
2402         }
2403
2404         /* renames options */
2405         else if (!prefixcmp(arg, "-B")) {
2406                 if ((options->break_opt = diff_scoreopt_parse(arg)) == -1)
2407                         return -1;
2408         }
2409         else if (!prefixcmp(arg, "-M")) {
2410                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2411                         return -1;
2412                 options->detect_rename = DIFF_DETECT_RENAME;
2413         }
2414         else if (!prefixcmp(arg, "-C")) {
2415                 if (options->detect_rename == DIFF_DETECT_COPY)
2416                         DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2417                 if ((options->rename_score = diff_scoreopt_parse(arg)) == -1)
2418                         return -1;
2419                 options->detect_rename = DIFF_DETECT_COPY;
2420         }
2421         else if (!strcmp(arg, "--no-renames"))
2422                 options->detect_rename = 0;
2423         else if (!strcmp(arg, "--relative"))
2424                 DIFF_OPT_SET(options, RELATIVE_NAME);
2425         else if (!prefixcmp(arg, "--relative=")) {
2426                 DIFF_OPT_SET(options, RELATIVE_NAME);
2427                 options->prefix = arg + 11;
2428         }
2429
2430         /* xdiff options */
2431         else if (!strcmp(arg, "-w") || !strcmp(arg, "--ignore-all-space"))
2432                 options->xdl_opts |= XDF_IGNORE_WHITESPACE;
2433         else if (!strcmp(arg, "-b") || !strcmp(arg, "--ignore-space-change"))
2434                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_CHANGE;
2435         else if (!strcmp(arg, "--ignore-space-at-eol"))
2436                 options->xdl_opts |= XDF_IGNORE_WHITESPACE_AT_EOL;
2437
2438         /* flags options */
2439         else if (!strcmp(arg, "--binary")) {
2440                 options->output_format |= DIFF_FORMAT_PATCH;
2441                 DIFF_OPT_SET(options, BINARY);
2442         }
2443         else if (!strcmp(arg, "--full-index"))
2444                 DIFF_OPT_SET(options, FULL_INDEX);
2445         else if (!strcmp(arg, "-a") || !strcmp(arg, "--text"))
2446                 DIFF_OPT_SET(options, TEXT);
2447         else if (!strcmp(arg, "-R"))
2448                 DIFF_OPT_SET(options, REVERSE_DIFF);
2449         else if (!strcmp(arg, "--find-copies-harder"))
2450                 DIFF_OPT_SET(options, FIND_COPIES_HARDER);
2451         else if (!strcmp(arg, "--follow"))
2452                 DIFF_OPT_SET(options, FOLLOW_RENAMES);
2453         else if (!strcmp(arg, "--color"))
2454                 DIFF_OPT_SET(options, COLOR_DIFF);
2455         else if (!strcmp(arg, "--no-color"))
2456                 DIFF_OPT_CLR(options, COLOR_DIFF);
2457         else if (!strcmp(arg, "--color-words"))
2458                 options->flags |= DIFF_OPT_COLOR_DIFF | DIFF_OPT_COLOR_DIFF_WORDS;
2459         else if (!strcmp(arg, "--exit-code"))
2460                 DIFF_OPT_SET(options, EXIT_WITH_STATUS);
2461         else if (!strcmp(arg, "--quiet"))
2462                 DIFF_OPT_SET(options, QUIET);
2463         else if (!strcmp(arg, "--ext-diff"))
2464                 DIFF_OPT_SET(options, ALLOW_EXTERNAL);
2465         else if (!strcmp(arg, "--no-ext-diff"))
2466                 DIFF_OPT_CLR(options, ALLOW_EXTERNAL);
2467
2468         /* misc options */
2469         else if (!strcmp(arg, "-z"))
2470                 options->line_termination = 0;
2471         else if (!prefixcmp(arg, "-l"))
2472                 options->rename_limit = strtoul(arg+2, NULL, 10);
2473         else if (!prefixcmp(arg, "-S"))
2474                 options->pickaxe = arg + 2;
2475         else if (!strcmp(arg, "--pickaxe-all"))
2476                 options->pickaxe_opts = DIFF_PICKAXE_ALL;
2477         else if (!strcmp(arg, "--pickaxe-regex"))
2478                 options->pickaxe_opts = DIFF_PICKAXE_REGEX;
2479         else if (!prefixcmp(arg, "-O"))
2480                 options->orderfile = arg + 2;
2481         else if (!prefixcmp(arg, "--diff-filter="))
2482                 options->filter = arg + 14;
2483         else if (!strcmp(arg, "--abbrev"))
2484                 options->abbrev = DEFAULT_ABBREV;
2485         else if (!prefixcmp(arg, "--abbrev=")) {
2486                 options->abbrev = strtoul(arg + 9, NULL, 10);
2487                 if (options->abbrev < MINIMUM_ABBREV)
2488                         options->abbrev = MINIMUM_ABBREV;
2489                 else if (40 < options->abbrev)
2490                         options->abbrev = 40;
2491         }
2492         else if (!prefixcmp(arg, "--src-prefix="))
2493                 options->a_prefix = arg + 13;
2494         else if (!prefixcmp(arg, "--dst-prefix="))
2495                 options->b_prefix = arg + 13;
2496         else if (!strcmp(arg, "--no-prefix"))
2497                 options->a_prefix = options->b_prefix = "";
2498         else if (!prefixcmp(arg, "--output=")) {
2499                 options->file = fopen(arg + strlen("--output="), "w");
2500                 options->close_file = 1;
2501         } else
2502                 return 0;
2503         return 1;
2504 }
2505
2506 static int parse_num(const char **cp_p)
2507 {
2508         unsigned long num, scale;
2509         int ch, dot;
2510         const char *cp = *cp_p;
2511
2512         num = 0;
2513         scale = 1;
2514         dot = 0;
2515         for(;;) {
2516                 ch = *cp;
2517                 if ( !dot && ch == '.' ) {
2518                         scale = 1;
2519                         dot = 1;
2520                 } else if ( ch == '%' ) {
2521                         scale = dot ? scale*100 : 100;
2522                         cp++;   /* % is always at the end */
2523                         break;
2524                 } else if ( ch >= '0' && ch <= '9' ) {
2525                         if ( scale < 100000 ) {
2526                                 scale *= 10;
2527                                 num = (num*10) + (ch-'0');
2528                         }
2529                 } else {
2530                         break;
2531                 }
2532                 cp++;
2533         }
2534         *cp_p = cp;
2535
2536         /* user says num divided by scale and we say internally that
2537          * is MAX_SCORE * num / scale.
2538          */
2539         return (int)((num >= scale) ? MAX_SCORE : (MAX_SCORE * num / scale));
2540 }
2541
2542 static int diff_scoreopt_parse(const char *opt)
2543 {
2544         int opt1, opt2, cmd;
2545
2546         if (*opt++ != '-')
2547                 return -1;
2548         cmd = *opt++;
2549         if (cmd != 'M' && cmd != 'C' && cmd != 'B')
2550                 return -1; /* that is not a -M, -C nor -B option */
2551
2552         opt1 = parse_num(&opt);
2553         if (cmd != 'B')
2554                 opt2 = 0;
2555         else {
2556                 if (*opt == 0)
2557                         opt2 = 0;
2558                 else if (*opt != '/')
2559                         return -1; /* we expect -B80/99 or -B80 */
2560                 else {
2561                         opt++;
2562                         opt2 = parse_num(&opt);
2563                 }
2564         }
2565         if (*opt != 0)
2566                 return -1;
2567         return opt1 | (opt2 << 16);
2568 }
2569
2570 struct diff_queue_struct diff_queued_diff;
2571
2572 void diff_q(struct diff_queue_struct *queue, struct diff_filepair *dp)
2573 {
2574         if (queue->alloc <= queue->nr) {
2575                 queue->alloc = alloc_nr(queue->alloc);
2576                 queue->queue = xrealloc(queue->queue,
2577                                         sizeof(dp) * queue->alloc);
2578         }
2579         queue->queue[queue->nr++] = dp;
2580 }
2581
2582 struct diff_filepair *diff_queue(struct diff_queue_struct *queue,
2583                                  struct diff_filespec *one,
2584                                  struct diff_filespec *two)
2585 {
2586         struct diff_filepair *dp = xcalloc(1, sizeof(*dp));
2587         dp->one = one;
2588         dp->two = two;
2589         if (queue)
2590                 diff_q(queue, dp);
2591         return dp;
2592 }
2593
2594 void diff_free_filepair(struct diff_filepair *p)
2595 {
2596         free_filespec(p->one);
2597         free_filespec(p->two);
2598         free(p);
2599 }
2600
2601 /* This is different from find_unique_abbrev() in that
2602  * it stuffs the result with dots for alignment.
2603  */
2604 const char *diff_unique_abbrev(const unsigned char *sha1, int len)
2605 {
2606         int abblen;
2607         const char *abbrev;
2608         if (len == 40)
2609                 return sha1_to_hex(sha1);
2610
2611         abbrev = find_unique_abbrev(sha1, len);
2612         abblen = strlen(abbrev);
2613         if (abblen < 37) {
2614                 static char hex[41];
2615                 if (len < abblen && abblen <= len + 2)
2616                         sprintf(hex, "%s%.*s", abbrev, len+3-abblen, "..");
2617                 else
2618                         sprintf(hex, "%s...", abbrev);
2619                 return hex;
2620         }
2621         return sha1_to_hex(sha1);
2622 }
2623
2624 static void diff_flush_raw(struct diff_filepair *p, struct diff_options *opt)
2625 {
2626         int line_termination = opt->line_termination;
2627         int inter_name_termination = line_termination ? '\t' : '\0';
2628
2629         if (!(opt->output_format & DIFF_FORMAT_NAME_STATUS)) {
2630                 fprintf(opt->file, ":%06o %06o %s ", p->one->mode, p->two->mode,
2631                         diff_unique_abbrev(p->one->sha1, opt->abbrev));
2632                 fprintf(opt->file, "%s ", diff_unique_abbrev(p->two->sha1, opt->abbrev));
2633         }
2634         if (p->score) {
2635                 fprintf(opt->file, "%c%03d%c", p->status, similarity_index(p),
2636                         inter_name_termination);
2637         } else {
2638                 fprintf(opt->file, "%c%c", p->status, inter_name_termination);
2639         }
2640
2641         if (p->status == DIFF_STATUS_COPIED ||
2642             p->status == DIFF_STATUS_RENAMED) {
2643                 const char *name_a, *name_b;
2644                 name_a = p->one->path;
2645                 name_b = p->two->path;
2646                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2647                 write_name_quoted(name_a, opt->file, inter_name_termination);
2648                 write_name_quoted(name_b, opt->file, line_termination);
2649         } else {
2650                 const char *name_a, *name_b;
2651                 name_a = p->one->mode ? p->one->path : p->two->path;
2652                 name_b = NULL;
2653                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2654                 write_name_quoted(name_a, opt->file, line_termination);
2655         }
2656 }
2657
2658 int diff_unmodified_pair(struct diff_filepair *p)
2659 {
2660         /* This function is written stricter than necessary to support
2661          * the currently implemented transformers, but the idea is to
2662          * let transformers to produce diff_filepairs any way they want,
2663          * and filter and clean them up here before producing the output.
2664          */
2665         struct diff_filespec *one = p->one, *two = p->two;
2666
2667         if (DIFF_PAIR_UNMERGED(p))
2668                 return 0; /* unmerged is interesting */
2669
2670         /* deletion, addition, mode or type change
2671          * and rename are all interesting.
2672          */
2673         if (DIFF_FILE_VALID(one) != DIFF_FILE_VALID(two) ||
2674             DIFF_PAIR_MODE_CHANGED(p) ||
2675             strcmp(one->path, two->path))
2676                 return 0;
2677
2678         /* both are valid and point at the same path.  that is, we are
2679          * dealing with a change.
2680          */
2681         if (one->sha1_valid && two->sha1_valid &&
2682             !hashcmp(one->sha1, two->sha1))
2683                 return 1; /* no change */
2684         if (!one->sha1_valid && !two->sha1_valid)
2685                 return 1; /* both look at the same file on the filesystem. */
2686         return 0;
2687 }
2688
2689 static void diff_flush_patch(struct diff_filepair *p, struct diff_options *o)
2690 {
2691         if (diff_unmodified_pair(p))
2692                 return;
2693
2694         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2695             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2696                 return; /* no tree diffs in patch format */
2697
2698         run_diff(p, o);
2699 }
2700
2701 static void diff_flush_stat(struct diff_filepair *p, struct diff_options *o,
2702                             struct diffstat_t *diffstat)
2703 {
2704         if (diff_unmodified_pair(p))
2705                 return;
2706
2707         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2708             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2709                 return; /* no tree diffs in patch format */
2710
2711         run_diffstat(p, o, diffstat);
2712 }
2713
2714 static void diff_flush_checkdiff(struct diff_filepair *p,
2715                 struct diff_options *o)
2716 {
2717         if (diff_unmodified_pair(p))
2718                 return;
2719
2720         if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2721             (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2722                 return; /* no tree diffs in patch format */
2723
2724         run_checkdiff(p, o);
2725 }
2726
2727 int diff_queue_is_empty(void)
2728 {
2729         struct diff_queue_struct *q = &diff_queued_diff;
2730         int i;
2731         for (i = 0; i < q->nr; i++)
2732                 if (!diff_unmodified_pair(q->queue[i]))
2733                         return 0;
2734         return 1;
2735 }
2736
2737 #if DIFF_DEBUG
2738 void diff_debug_filespec(struct diff_filespec *s, int x, const char *one)
2739 {
2740         fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
2741                 x, one ? one : "",
2742                 s->path,
2743                 DIFF_FILE_VALID(s) ? "valid" : "invalid",
2744                 s->mode,
2745                 s->sha1_valid ? sha1_to_hex(s->sha1) : "");
2746         fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
2747                 x, one ? one : "",
2748                 s->size, s->xfrm_flags);
2749 }
2750
2751 void diff_debug_filepair(const struct diff_filepair *p, int i)
2752 {
2753         diff_debug_filespec(p->one, i, "one");
2754         diff_debug_filespec(p->two, i, "two");
2755         fprintf(stderr, "score %d, status %c rename_used %d broken %d\n",
2756                 p->score, p->status ? p->status : '?',
2757                 p->one->rename_used, p->broken_pair);
2758 }
2759
2760 void diff_debug_queue(const char *msg, struct diff_queue_struct *q)
2761 {
2762         int i;
2763         if (msg)
2764                 fprintf(stderr, "%s\n", msg);
2765         fprintf(stderr, "q->nr = %d\n", q->nr);
2766         for (i = 0; i < q->nr; i++) {
2767                 struct diff_filepair *p = q->queue[i];
2768                 diff_debug_filepair(p, i);
2769         }
2770 }
2771 #endif
2772
2773 static void diff_resolve_rename_copy(void)
2774 {
2775         int i;
2776         struct diff_filepair *p;
2777         struct diff_queue_struct *q = &diff_queued_diff;
2778
2779         diff_debug_queue("resolve-rename-copy", q);
2780
2781         for (i = 0; i < q->nr; i++) {
2782                 p = q->queue[i];
2783                 p->status = 0; /* undecided */
2784                 if (DIFF_PAIR_UNMERGED(p))
2785                         p->status = DIFF_STATUS_UNMERGED;
2786                 else if (!DIFF_FILE_VALID(p->one))
2787                         p->status = DIFF_STATUS_ADDED;
2788                 else if (!DIFF_FILE_VALID(p->two))
2789                         p->status = DIFF_STATUS_DELETED;
2790                 else if (DIFF_PAIR_TYPE_CHANGED(p))
2791                         p->status = DIFF_STATUS_TYPE_CHANGED;
2792
2793                 /* from this point on, we are dealing with a pair
2794                  * whose both sides are valid and of the same type, i.e.
2795                  * either in-place edit or rename/copy edit.
2796                  */
2797                 else if (DIFF_PAIR_RENAME(p)) {
2798                         /*
2799                          * A rename might have re-connected a broken
2800                          * pair up, causing the pathnames to be the
2801                          * same again. If so, that's not a rename at
2802                          * all, just a modification..
2803                          *
2804                          * Otherwise, see if this source was used for
2805                          * multiple renames, in which case we decrement
2806                          * the count, and call it a copy.
2807                          */
2808                         if (!strcmp(p->one->path, p->two->path))
2809                                 p->status = DIFF_STATUS_MODIFIED;
2810                         else if (--p->one->rename_used > 0)
2811                                 p->status = DIFF_STATUS_COPIED;
2812                         else
2813                                 p->status = DIFF_STATUS_RENAMED;
2814                 }
2815                 else if (hashcmp(p->one->sha1, p->two->sha1) ||
2816                          p->one->mode != p->two->mode ||
2817                          is_null_sha1(p->one->sha1))
2818                         p->status = DIFF_STATUS_MODIFIED;
2819                 else {
2820                         /* This is a "no-change" entry and should not
2821                          * happen anymore, but prepare for broken callers.
2822                          */
2823                         error("feeding unmodified %s to diffcore",
2824                               p->one->path);
2825                         p->status = DIFF_STATUS_UNKNOWN;
2826                 }
2827         }
2828         diff_debug_queue("resolve-rename-copy done", q);
2829 }
2830
2831 static int check_pair_status(struct diff_filepair *p)
2832 {
2833         switch (p->status) {
2834         case DIFF_STATUS_UNKNOWN:
2835                 return 0;
2836         case 0:
2837                 die("internal error in diff-resolve-rename-copy");
2838         default:
2839                 return 1;
2840         }
2841 }
2842
2843 static void flush_one_pair(struct diff_filepair *p, struct diff_options *opt)
2844 {
2845         int fmt = opt->output_format;
2846
2847         if (fmt & DIFF_FORMAT_CHECKDIFF)
2848                 diff_flush_checkdiff(p, opt);
2849         else if (fmt & (DIFF_FORMAT_RAW | DIFF_FORMAT_NAME_STATUS))
2850                 diff_flush_raw(p, opt);
2851         else if (fmt & DIFF_FORMAT_NAME) {
2852                 const char *name_a, *name_b;
2853                 name_a = p->two->path;
2854                 name_b = NULL;
2855                 strip_prefix(opt->prefix_length, &name_a, &name_b);
2856                 write_name_quoted(name_a, opt->file, opt->line_termination);
2857         }
2858 }
2859
2860 static void show_file_mode_name(FILE *file, const char *newdelete, struct diff_filespec *fs)
2861 {
2862         if (fs->mode)
2863                 fprintf(file, " %s mode %06o ", newdelete, fs->mode);
2864         else
2865                 fprintf(file, " %s ", newdelete);
2866         write_name_quoted(fs->path, file, '\n');
2867 }
2868
2869
2870 static void show_mode_change(FILE *file, struct diff_filepair *p, int show_name)
2871 {
2872         if (p->one->mode && p->two->mode && p->one->mode != p->two->mode) {
2873                 fprintf(file, " mode change %06o => %06o%c", p->one->mode, p->two->mode,
2874                         show_name ? ' ' : '\n');
2875                 if (show_name) {
2876                         write_name_quoted(p->two->path, file, '\n');
2877                 }
2878         }
2879 }
2880
2881 static void show_rename_copy(FILE *file, const char *renamecopy, struct diff_filepair *p)
2882 {
2883         char *names = pprint_rename(p->one->path, p->two->path);
2884
2885         fprintf(file, " %s %s (%d%%)\n", renamecopy, names, similarity_index(p));
2886         free(names);
2887         show_mode_change(file, p, 0);
2888 }
2889
2890 static void diff_summary(FILE *file, struct diff_filepair *p)
2891 {
2892         switch(p->status) {
2893         case DIFF_STATUS_DELETED:
2894                 show_file_mode_name(file, "delete", p->one);
2895                 break;
2896         case DIFF_STATUS_ADDED:
2897                 show_file_mode_name(file, "create", p->two);
2898                 break;
2899         case DIFF_STATUS_COPIED:
2900                 show_rename_copy(file, "copy", p);
2901                 break;
2902         case DIFF_STATUS_RENAMED:
2903                 show_rename_copy(file, "rename", p);
2904                 break;
2905         default:
2906                 if (p->score) {
2907                         fputs(" rewrite ", file);
2908                         write_name_quoted(p->two->path, file, ' ');
2909                         fprintf(file, "(%d%%)\n", similarity_index(p));
2910                 }
2911                 show_mode_change(file, p, !p->score);
2912                 break;
2913         }
2914 }
2915
2916 struct patch_id_t {
2917         struct xdiff_emit_state xm;
2918         SHA_CTX *ctx;
2919         int patchlen;
2920 };
2921
2922 static int remove_space(char *line, int len)
2923 {
2924         int i;
2925         char *dst = line;
2926         unsigned char c;
2927
2928         for (i = 0; i < len; i++)
2929                 if (!isspace((c = line[i])))
2930                         *dst++ = c;
2931
2932         return dst - line;
2933 }
2934
2935 static void patch_id_consume(void *priv, char *line, unsigned long len)
2936 {
2937         struct patch_id_t *data = priv;
2938         int new_len;
2939
2940         /* Ignore line numbers when computing the SHA1 of the patch */
2941         if (!prefixcmp(line, "@@ -"))
2942                 return;
2943
2944         new_len = remove_space(line, len);
2945
2946         SHA1_Update(data->ctx, line, new_len);
2947         data->patchlen += new_len;
2948 }
2949
2950 /* returns 0 upon success, and writes result into sha1 */
2951 static int diff_get_patch_id(struct diff_options *options, unsigned char *sha1)
2952 {
2953         struct diff_queue_struct *q = &diff_queued_diff;
2954         int i;
2955         SHA_CTX ctx;
2956         struct patch_id_t data;
2957         char buffer[PATH_MAX * 4 + 20];
2958
2959         SHA1_Init(&ctx);
2960         memset(&data, 0, sizeof(struct patch_id_t));
2961         data.ctx = &ctx;
2962         data.xm.consume = patch_id_consume;
2963
2964         for (i = 0; i < q->nr; i++) {
2965                 xpparam_t xpp;
2966                 xdemitconf_t xecfg;
2967                 xdemitcb_t ecb;
2968                 mmfile_t mf1, mf2;
2969                 struct diff_filepair *p = q->queue[i];
2970                 int len1, len2;
2971
2972                 memset(&xecfg, 0, sizeof(xecfg));
2973                 if (p->status == 0)
2974                         return error("internal diff status error");
2975                 if (p->status == DIFF_STATUS_UNKNOWN)
2976                         continue;
2977                 if (diff_unmodified_pair(p))
2978                         continue;
2979                 if ((DIFF_FILE_VALID(p->one) && S_ISDIR(p->one->mode)) ||
2980                     (DIFF_FILE_VALID(p->two) && S_ISDIR(p->two->mode)))
2981                         continue;
2982                 if (DIFF_PAIR_UNMERGED(p))
2983                         continue;
2984
2985                 diff_fill_sha1_info(p->one);
2986                 diff_fill_sha1_info(p->two);
2987                 if (fill_mmfile(&mf1, p->one) < 0 ||
2988                                 fill_mmfile(&mf2, p->two) < 0)
2989                         return error("unable to read files to diff");
2990
2991                 len1 = remove_space(p->one->path, strlen(p->one->path));
2992                 len2 = remove_space(p->two->path, strlen(p->two->path));
2993                 if (p->one->mode == 0)
2994                         len1 = snprintf(buffer, sizeof(buffer),
2995                                         "diff--gita/%.*sb/%.*s"
2996                                         "newfilemode%06o"
2997                                         "---/dev/null"
2998                                         "+++b/%.*s",
2999                                         len1, p->one->path,
3000                                         len2, p->two->path,
3001                                         p->two->mode,
3002                                         len2, p->two->path);
3003                 else if (p->two->mode == 0)
3004                         len1 = snprintf(buffer, sizeof(buffer),
3005                                         "diff--gita/%.*sb/%.*s"
3006                                         "deletedfilemode%06o"
3007                                         "---a/%.*s"
3008                                         "+++/dev/null",
3009                                         len1, p->one->path,
3010                                         len2, p->two->path,
3011                                         p->one->mode,
3012                                         len1, p->one->path);
3013                 else
3014                         len1 = snprintf(buffer, sizeof(buffer),
3015                                         "diff--gita/%.*sb/%.*s"
3016                                         "---a/%.*s"
3017                                         "+++b/%.*s",
3018                                         len1, p->one->path,
3019                                         len2, p->two->path,
3020                                         len1, p->one->path,
3021                                         len2, p->two->path);
3022                 SHA1_Update(&ctx, buffer, len1);
3023
3024                 xpp.flags = XDF_NEED_MINIMAL;
3025                 xecfg.ctxlen = 3;
3026                 xecfg.flags = XDL_EMIT_FUNCNAMES;
3027                 ecb.outf = xdiff_outf;
3028                 ecb.priv = &data;
3029                 xdi_diff(&mf1, &mf2, &xpp, &xecfg, &ecb);
3030         }
3031
3032         SHA1_Final(sha1, &ctx);
3033         return 0;
3034 }
3035
3036 int diff_flush_patch_id(struct diff_options *options, unsigned char *sha1)
3037 {
3038         struct diff_queue_struct *q = &diff_queued_diff;
3039         int i;
3040         int result = diff_get_patch_id(options, sha1);
3041
3042         for (i = 0; i < q->nr; i++)
3043                 diff_free_filepair(q->queue[i]);
3044
3045         free(q->queue);
3046         q->queue = NULL;
3047         q->nr = q->alloc = 0;
3048
3049         return result;
3050 }
3051
3052 static int is_summary_empty(const struct diff_queue_struct *q)
3053 {
3054         int i;
3055
3056         for (i = 0; i < q->nr; i++) {
3057                 const struct diff_filepair *p = q->queue[i];
3058
3059                 switch (p->status) {
3060                 case DIFF_STATUS_DELETED:
3061                 case DIFF_STATUS_ADDED:
3062                 case DIFF_STATUS_COPIED:
3063                 case DIFF_STATUS_RENAMED:
3064                         return 0;
3065                 default:
3066                         if (p->score)
3067                                 return 0;
3068                         if (p->one->mode && p->two->mode &&
3069                             p->one->mode != p->two->mode)
3070                                 return 0;
3071                         break;
3072                 }
3073         }
3074         return 1;
3075 }
3076
3077 void diff_flush(struct diff_options *options)
3078 {
3079         struct diff_queue_struct *q = &diff_queued_diff;
3080         int i, output_format = options->output_format;
3081         int separator = 0;
3082
3083         /*
3084          * Order: raw, stat, summary, patch
3085          * or:    name/name-status/checkdiff (other bits clear)
3086          */
3087         if (!q->nr)
3088                 goto free_queue;
3089
3090         if (output_format & (DIFF_FORMAT_RAW |
3091                              DIFF_FORMAT_NAME |
3092                              DIFF_FORMAT_NAME_STATUS |
3093                              DIFF_FORMAT_CHECKDIFF)) {
3094                 for (i = 0; i < q->nr; i++) {
3095                         struct diff_filepair *p = q->queue[i];
3096                         if (check_pair_status(p))
3097                                 flush_one_pair(p, options);
3098                 }
3099                 separator++;
3100         }
3101
3102         if (output_format & (DIFF_FORMAT_DIFFSTAT|DIFF_FORMAT_SHORTSTAT|DIFF_FORMAT_NUMSTAT|DIFF_FORMAT_DIRSTAT)) {
3103                 struct diffstat_t diffstat;
3104
3105                 memset(&diffstat, 0, sizeof(struct diffstat_t));
3106                 diffstat.xm.consume = diffstat_consume;
3107                 for (i = 0; i < q->nr; i++) {
3108                         struct diff_filepair *p = q->queue[i];
3109                         if (check_pair_status(p))
3110                                 diff_flush_stat(p, options, &diffstat);
3111                 }
3112                 if (output_format & DIFF_FORMAT_DIRSTAT)
3113                         show_dirstat(&diffstat, options);
3114                 if (output_format & DIFF_FORMAT_NUMSTAT)
3115                         show_numstat(&diffstat, options);
3116                 if (output_format & DIFF_FORMAT_DIFFSTAT)
3117                         show_stats(&diffstat, options);
3118                 if (output_format & DIFF_FORMAT_SHORTSTAT)
3119                         show_shortstats(&diffstat, options);
3120                 free_diffstat_info(&diffstat);
3121                 separator++;
3122         }
3123
3124         if (output_format & DIFF_FORMAT_SUMMARY && !is_summary_empty(q)) {
3125                 for (i = 0; i < q->nr; i++)
3126                         diff_summary(options->file, q->queue[i]);
3127                 separator++;
3128         }
3129
3130         if (output_format & DIFF_FORMAT_PATCH) {
3131                 if (separator) {
3132                         if (options->stat_sep) {
3133                                 /* attach patch instead of inline */
3134                                 fputs(options->stat_sep, options->file);
3135                         } else {
3136                                 putc(options->line_termination, options->file);
3137                         }
3138                 }
3139
3140                 for (i = 0; i < q->nr; i++) {
3141                         struct diff_filepair *p = q->queue[i];
3142                         if (check_pair_status(p))
3143                                 diff_flush_patch(p, options);
3144                 }
3145         }
3146
3147         if (output_format & DIFF_FORMAT_CALLBACK)
3148                 options->format_callback(q, options, options->format_callback_data);
3149
3150         for (i = 0; i < q->nr; i++)
3151                 diff_free_filepair(q->queue[i]);
3152 free_queue:
3153         free(q->queue);
3154         q->queue = NULL;
3155         q->nr = q->alloc = 0;
3156         if (options->close_file)
3157                 fclose(options->file);
3158 }
3159
3160 static void diffcore_apply_filter(const char *filter)
3161 {
3162         int i;
3163         struct diff_queue_struct *q = &diff_queued_diff;
3164         struct diff_queue_struct outq;
3165         outq.queue = NULL;
3166         outq.nr = outq.alloc = 0;
3167
3168         if (!filter)
3169                 return;
3170
3171         if (strchr(filter, DIFF_STATUS_FILTER_AON)) {
3172                 int found;
3173                 for (i = found = 0; !found && i < q->nr; i++) {
3174                         struct diff_filepair *p = q->queue[i];
3175                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3176                              ((p->score &&
3177                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3178                               (!p->score &&
3179                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3180                             ((p->status != DIFF_STATUS_MODIFIED) &&
3181                              strchr(filter, p->status)))
3182                                 found++;
3183                 }
3184                 if (found)
3185                         return;
3186
3187                 /* otherwise we will clear the whole queue
3188                  * by copying the empty outq at the end of this
3189                  * function, but first clear the current entries
3190                  * in the queue.
3191                  */
3192                 for (i = 0; i < q->nr; i++)
3193                         diff_free_filepair(q->queue[i]);
3194         }
3195         else {
3196                 /* Only the matching ones */
3197                 for (i = 0; i < q->nr; i++) {
3198                         struct diff_filepair *p = q->queue[i];
3199
3200                         if (((p->status == DIFF_STATUS_MODIFIED) &&
3201                              ((p->score &&
3202                                strchr(filter, DIFF_STATUS_FILTER_BROKEN)) ||
3203                               (!p->score &&
3204                                strchr(filter, DIFF_STATUS_MODIFIED)))) ||
3205                             ((p->status != DIFF_STATUS_MODIFIED) &&
3206                              strchr(filter, p->status)))
3207                                 diff_q(&outq, p);
3208                         else
3209                                 diff_free_filepair(p);
3210                 }
3211         }
3212         free(q->queue);
3213         *q = outq;
3214 }
3215
3216 /* Check whether two filespecs with the same mode and size are identical */
3217 static int diff_filespec_is_identical(struct diff_filespec *one,
3218                                       struct diff_filespec *two)
3219 {
3220         if (S_ISGITLINK(one->mode))
3221                 return 0;
3222         if (diff_populate_filespec(one, 0))
3223                 return 0;
3224         if (diff_populate_filespec(two, 0))
3225                 return 0;
3226         return !memcmp(one->data, two->data, one->size);
3227 }
3228
3229 static void diffcore_skip_stat_unmatch(struct diff_options *diffopt)
3230 {
3231         int i;
3232         struct diff_queue_struct *q = &diff_queued_diff;
3233         struct diff_queue_struct outq;
3234         outq.queue = NULL;
3235         outq.nr = outq.alloc = 0;
3236
3237         for (i = 0; i < q->nr; i++) {
3238                 struct diff_filepair *p = q->queue[i];
3239
3240                 /*
3241                  * 1. Entries that come from stat info dirtyness
3242                  *    always have both sides (iow, not create/delete),
3243                  *    one side of the object name is unknown, with
3244                  *    the same mode and size.  Keep the ones that
3245                  *    do not match these criteria.  They have real
3246                  *    differences.
3247                  *
3248                  * 2. At this point, the file is known to be modified,
3249                  *    with the same mode and size, and the object
3250                  *    name of one side is unknown.  Need to inspect
3251                  *    the identical contents.
3252                  */
3253                 if (!DIFF_FILE_VALID(p->one) || /* (1) */
3254                     !DIFF_FILE_VALID(p->two) ||
3255                     (p->one->sha1_valid && p->two->sha1_valid) ||
3256                     (p->one->mode != p->two->mode) ||
3257                     diff_populate_filespec(p->one, 1) ||
3258                     diff_populate_filespec(p->two, 1) ||
3259                     (p->one->size != p->two->size) ||
3260                     !diff_filespec_is_identical(p->one, p->two)) /* (2) */
3261                         diff_q(&outq, p);
3262                 else {
3263                         /*
3264                          * The caller can subtract 1 from skip_stat_unmatch
3265                          * to determine how many paths were dirty only
3266                          * due to stat info mismatch.
3267                          */
3268                         if (!DIFF_OPT_TST(diffopt, NO_INDEX))
3269                                 diffopt->skip_stat_unmatch++;
3270                         diff_free_filepair(p);
3271                 }
3272         }
3273         free(q->queue);
3274         *q = outq;
3275 }
3276
3277 void diffcore_std(struct diff_options *options)
3278 {
3279         if (DIFF_OPT_TST(options, QUIET))
3280                 return;
3281
3282         if (options->skip_stat_unmatch && !DIFF_OPT_TST(options, FIND_COPIES_HARDER))
3283                 diffcore_skip_stat_unmatch(options);
3284         if (options->break_opt != -1)
3285                 diffcore_break(options->break_opt);
3286         if (options->detect_rename)
3287                 diffcore_rename(options);
3288         if (options->break_opt != -1)
3289                 diffcore_merge_broken();
3290         if (options->pickaxe)
3291                 diffcore_pickaxe(options->pickaxe, options->pickaxe_opts);
3292         if (options->orderfile)
3293                 diffcore_order(options->orderfile);
3294         diff_resolve_rename_copy();
3295         diffcore_apply_filter(options->filter);
3296
3297         if (diff_queued_diff.nr)
3298                 DIFF_OPT_SET(options, HAS_CHANGES);
3299         else
3300                 DIFF_OPT_CLR(options, HAS_CHANGES);
3301 }
3302
3303 int diff_result_code(struct diff_options *opt, int status)
3304 {
3305         int result = 0;
3306         if (!DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3307             !(opt->output_format & DIFF_FORMAT_CHECKDIFF))
3308                 return status;
3309         if (DIFF_OPT_TST(opt, EXIT_WITH_STATUS) &&
3310             DIFF_OPT_TST(opt, HAS_CHANGES))
3311                 result |= 01;
3312         if ((opt->output_format & DIFF_FORMAT_CHECKDIFF) &&
3313             DIFF_OPT_TST(opt, CHECK_FAILED))
3314                 result |= 02;
3315         return result;
3316 }
3317
3318 void diff_addremove(struct diff_options *options,
3319                     int addremove, unsigned mode,
3320                     const unsigned char *sha1,
3321                     const char *base, const char *path)
3322 {
3323         char concatpath[PATH_MAX];
3324         struct diff_filespec *one, *two;
3325
3326         /* This may look odd, but it is a preparation for
3327          * feeding "there are unchanged files which should
3328          * not produce diffs, but when you are doing copy
3329          * detection you would need them, so here they are"
3330          * entries to the diff-core.  They will be prefixed
3331          * with something like '=' or '*' (I haven't decided
3332          * which but should not make any difference).
3333          * Feeding the same new and old to diff_change()
3334          * also has the same effect.
3335          * Before the final output happens, they are pruned after
3336          * merged into rename/copy pairs as appropriate.
3337          */
3338         if (DIFF_OPT_TST(options, REVERSE_DIFF))
3339                 addremove = (addremove == '+' ? '-' :
3340                              addremove == '-' ? '+' : addremove);
3341
3342         if (!path) path = "";
3343         sprintf(concatpath, "%s%s", base, path);
3344
3345         if (options->prefix &&
3346             strncmp(concatpath, options->prefix, options->prefix_length))
3347                 return;
3348
3349         one = alloc_filespec(concatpath);
3350         two = alloc_filespec(concatpath);
3351
3352         if (addremove != '+')
3353                 fill_filespec(one, sha1, mode);
3354         if (addremove != '-')
3355                 fill_filespec(two, sha1, mode);
3356
3357         diff_queue(&diff_queued_diff, one, two);
3358         DIFF_OPT_SET(options, HAS_CHANGES);
3359 }
3360
3361 void diff_change(struct diff_options *options,
3362                  unsigned old_mode, unsigned new_mode,
3363                  const unsigned char *old_sha1,
3364                  const unsigned char *new_sha1,
3365                  const char *base, const char *path)
3366 {
3367         char concatpath[PATH_MAX];
3368         struct diff_filespec *one, *two;
3369
3370         if (DIFF_OPT_TST(options, REVERSE_DIFF)) {
3371                 unsigned tmp;
3372                 const unsigned char *tmp_c;
3373                 tmp = old_mode; old_mode = new_mode; new_mode = tmp;
3374                 tmp_c = old_sha1; old_sha1 = new_sha1; new_sha1 = tmp_c;
3375         }
3376         if (!path) path = "";
3377         sprintf(concatpath, "%s%s", base, path);
3378
3379         if (options->prefix &&
3380             strncmp(concatpath, options->prefix, options->prefix_length))
3381                 return;
3382
3383         one = alloc_filespec(concatpath);
3384         two = alloc_filespec(concatpath);
3385         fill_filespec(one, old_sha1, old_mode);
3386         fill_filespec(two, new_sha1, new_mode);
3387
3388         diff_queue(&diff_queued_diff, one, two);
3389         DIFF_OPT_SET(options, HAS_CHANGES);
3390 }
3391
3392 void diff_unmerge(struct diff_options *options,
3393                   const char *path,
3394                   unsigned mode, const unsigned char *sha1)
3395 {
3396         struct diff_filespec *one, *two;
3397
3398         if (options->prefix &&
3399             strncmp(path, options->prefix, options->prefix_length))
3400                 return;
3401
3402         one = alloc_filespec(path);
3403         two = alloc_filespec(path);
3404         fill_filespec(one, sha1, mode);
3405         diff_queue(&diff_queued_diff, one, two)->is_unmerged = 1;
3406 }